WorldWideScience

Sample records for river aquifer interactions

  1. Characterizing the Impact of River Barrage Construction on Stream-Aquifer Interactions, Korea

    Directory of Open Access Journals (Sweden)

    Yun-Yeong Oh

    2016-04-01

    Full Text Available This study investigated changes in stream–aquifer interactions during the period shortly after the construction of the Changnyeong-Haman River barrage (CHRB on the Nakdong River in South Korea. The hydraulic diffusivity (α and river resistance (R values at the semipervious stream–aquifer interface were estimated by using a one-dimensional (1-D analytical solution with Fourier transform (FT. Prior to the application of the 1-D analytical solution, the noise effects on the groundwater levels were removed by using fast Fourier transform and low-pass filtering techniques. Sinusoidal variation of the river stages was applied to the 1-D analytical solution. For the study period, the R values showed a decreasing trend, while the α values showed an increasing trend, and results showed that the average of the median values of flood duration times (td and flood amplitudes were reduced to 78% and 59%, respectively. Moreover, the ratio of flood peak time to td demonstrated a decreasing tendency after the construction of the CHRB. Hence, it is concluded that the dredging and increase of river-water storage due to CHRB construction enhanced stream–aquifer interactions during the period shortly after the construction of the CHRB.

  2. The nitrogen cycle in highly urbanized tropical regions and the effect of river-aquifer interactions: The case of Jakarta and the Ciliwung River

    Science.gov (United States)

    Costa, Diogo; Burlando, Paolo; Priadi, Cindy; Shie-Yui, Liong

    2016-09-01

    Groundwater is extensively used in Jakarta to compensate for the limited public water supply network. Recent observations show a rise in nitrate (NO3-) levels in the shallow aquifer, thus pointing at a potential risk for public health. The detected levels are still below national and international regulatory limits for drinking water but a strategy is necessary to contain the growing problem. We combine 3 years of available data in the Ciliwung River, the major river flowing through Jakarta, with a distributed river-aquifer interaction model to characterise the impact of urbanisation on the N-cycle of both surface and groundwater systems. Results show that the N-cycle in the river-aquifer system is heterogeneous in space, seasonal dependent (i.e. flow regime) and strongly affected by urban pollution. Results suggest also that although the main sources of N related groundwater pollution are leaking septic tanks, the aquifer interaction with the Ciliwung River may locally have a strong effect on the concentrations. In the general context of pollution control in urban areas, this study demonstrates how advanced process-based models can be efficiently used in combination with field measurements to bring new insights into complex contamination problems. These are essential for more effective and integrated management of water quality in river-aquifer systems.

  3. Interaction of Aquifer and River-Canal Network near Well Field.

    Science.gov (United States)

    Ghosh, Narayan C; Mishra, Govinda C; Sandhu, Cornelius S S; Grischek, Thomas; Singh, Vikrant V

    2015-01-01

    The article presents semi-analytical mathematical models to asses (1) enhancements of seepage from a canal and (2) induced flow from a partially penetrating river in an unconfined aquifer consequent to groundwater withdrawal in a well field in the vicinity of the river and canal. The nonlinear exponential relation between seepage from a canal reach and hydraulic head in the aquifer beneath the canal reach is used for quantifying seepage from the canal reach. Hantush's (1967) basic solution for water table rise due to recharge from a rectangular spreading basin in absence of pumping well is used for generating unit pulse response function coefficients for water table rise in the aquifer. Duhamel's convolution theory and method of superposition are applied to obtain water table position due to pumping and recharge from different canal reaches. Hunt's (1999) basic solution for river depletion due to constant pumping from a well in the vicinity of a partially penetrating river is used to generate unit pulse response function coefficients. Applying convolution technique and superposition, treating the recharge from canal reaches as recharge through conceptual injection wells, river depletion consequent to variable pumping and recharge is quantified. The integrated model is applied to a case study in Haridwar (India). The well field consists of 22 pumping wells located in the vicinity of a perennial river and a canal network. The river bank filtrate portion consequent to pumping is quantified. © 2014, National GroundWater Association.

  4. To what extent do long-duration high-volume dam releases influence river-aquifer interactions? A case study in New South Wales, Australia

    Science.gov (United States)

    Graham, P. W.; Andersen, M. S.; McCabe, M. F.; Ajami, H.; Baker, A.; Acworth, I.

    2015-03-01

    Long-duration high-volume dam releases are unique anthropogenic events with no naturally occurring equivalents. The impact from such dam releases on a downstream Quaternary alluvial aquifer in New South Wales, Australia, is assessed. It is observed that long-duration (>26 days), high-volume dam releases (>8,000 ML/day average) result in significant variations in river-aquifer interactions. These variations include a flux from the river to the aquifer up to 6.3 m3/day per metre of bank (at distances of up to 330 m from the river bank), increased extent and volume of recharge/bank storage, and a long-term (>100 days) reversal of river-aquifer fluxes. In contrast, during lower-volume events (bank. A groundwater-head prediction model was constructed and river-aquifer fluxes were calculated; however, predicted fluxes from this method showed poor correlation to fluxes calculated using actual groundwater heads. Long-duration high-volume dam releases have the potential to skew estimates of long-term aquifer resources and detrimentally alter the chemical and physical properties of phreatic aquifers flanking the river. The findings have ramifications for improved integrated management of dam systems and downstream aquifers.

  5. The study of the interactions between groundwater and Sava River water in the Ljubljansko polje aquifer system (Slovenia)

    Science.gov (United States)

    Vrzel, Janja; Solomon, D. Kip; Blažeka, Željko; Ogrinc, Nives

    2018-01-01

    River basin aquifers are common sites for drinking water wells as bank filtration can be a cost effective pretreatment technology. A groundwater vulnerability to pollution depends on a groundwater mean residence time and on a relative contribution of river water versus local precipitation to groundwater. Environmental isotopes of oxygen and hydrogen (δ18O and δ2H), tritium (3H) and concentrations of nitrate (NO3-) were used to investigate hydrological pathways, mean residence time and interactions between surface water and groundwater in the Ljubljansko polje aquifer system in Slovenia. δ18O and δ2H values indicate a spatial variability of the influence of individual groundwater sources inside the aquifer - local precipitation and the Sava River water. Fractions of river water in groundwater depend on the depth of perforated screens in the pumping wells and their distance from the Sava River. It was estimated that groundwater at wells Kleče 11, Hrastje 3, and Hrastje 8 is mostly composed of recently infiltrated local precipitation, while the Sava River is the dominant source of groundwater at the well Jarški prod 1. Groundwater at wells Kleče 8, Kleče 12, and Jarški prod 3 contains on average between 41% and 48% of the Sava River water. The 3H and 3H/3He methods indicate short mean residence time of groundwater present at Jarški prod (2-7 years) and Hrastje (7-8 years). A small fraction (pollution.

  6. The Contribution of the Future SWOT Mission to Improve Simulations of River Stages and Stream-Aquifer Interactions at Regional Scale

    Science.gov (United States)

    Saleh, Firas; Filipo, Nicolas; Biancamaria, Sylvain; Habets, Florence; Rodriguez, Enersto; Mognard, Nelly

    2013-09-01

    The main objective of this study is to provide a realistic simulation of river stage in regional river networks in order to improve the quantification of stream-aquifer exchanges and better assess the associated aquifer responses that are often impacted by the magnitude and the frequency of the river stage fluctuations. This study extends the earlier work to improve the modeling of the Seine basin with a focus on simulating the hydrodynamics behavior of the Bassée alluvial wetland, a 120 km reach of the Seine River valley located south- east of Paris. The Bassée is of major importance for the drinking-water supply of Paris and surroundings, in addition to its particular hydrodynamic behavior due to the presence of a number of gravels. In this context, the understanding of stream-aquifer interactions is required for water quantity and quality preservation. A regional distributed process-based hydro(geo)logical model, Eau-Dyssée, is used. It aims at the integrated modeling of the hydrosystem to manage the various elements involved in the quantitative and qualitative aspects of water resources. Eau-Dyssée simulates pseudo 3D flow in aquifer systems solving the diffusivity equation with a finite difference numerical scheme. River flow is simulated with a Muskingum model. In addition to the in-stream discharge, a river stage estimate is needed to calculate the water exchange at the stream-aquifer interface using a conductance model. In this context, the future SWOT mission and its high-spatial resolution imagery can provide surface water level measurements at the regional scale that will permit to better characterize the Bassée complex hydro(geo)logical system and better assess soil water content. Moreover, the Bassée is considered as a potential target for the framework of the AirSWOT airborne campaign in France, 2013.

  7. San Pedro River Aquifer Binational Report

    Science.gov (United States)

    Callegary, James B.; Minjárez Sosa, Ismael; Tapia Villaseñor, Elia María; dos Santos, Placido; Monreal Saavedra, Rogelio; Grijalva Noriega, Franciso Javier; Huth, A. K.; Gray, Floyd; Scott, C. A.; Megdal, Sharon; Oroz Ramos, L. A.; Rangel Medina, Miguel; Leenhouts, James M.

    2016-01-01

    use new and existing research to define the general hydrologic framework of the Binational San Pedro Aquifer (BSPA), to gather hydrogeological and other relevant data in preparation for future work such as an updated groundwater conceptual model and budget and to establish the basis for a binational numerical model. The specific objectives are as follows:Understand the current state of knowledge with respect to climate, geology, soils, land cover, land use, and hydrology of the aquifer in its binational context;Compile and create a database of scientific information from both countries;Identify data gaps and identify what data would be necessary to update, in a subsequent phase, the hydrologic model of the aquifer system, including surface- and groundwater interactions on a binational level.The BSPB is one of the most studied basins in the region, and a database of publications has been compiled as part of this project. Previous studies include topics that range from geophysics and hydrogeology to biology and ecosystem services. The economic drivers on each side of the border are quite different. In the Arizona 4 portion of the basin military and tourism dominate while in the Sonoran portion, mining is the most important industry. Water management is also different in the two countries. In Mexico, primary authority for management of water resources devolves from the federal government. In the United States, primary authority rests with the states except in cases of interstate surface waters. Binational waters are not currently jointly managed by the two countries except in cases where treaties have been negotiated such as for the Rio Grande and Colorado Rivers. Thus, there is currently no binational coordination or treaty governing the management of groundwater.

  8. Development of A Mississippi River Alluvial Aquifer Groundwater Model

    Science.gov (United States)

    Karakullukcu, R. E.; Tsai, F. T. C.; Bhatta, D.; Paudel, K.; Kao, S. C.

    2017-12-01

    The Mississippi River Alluvial Aquifer (MRAA) underlies the Mississippi River Valley of the northeastern Louisiana, extending from the north border of Louisiana and Arkansas to south central of Louisiana. The MRAA has direct contact with the Mississippi River. However, the interaction between the Mississippi River and the alluvial aquifer is largely unknown. The MRAA is the second most used groundwater source in Louisiana's aquifers with about 390 million gallons per day, which is about 25% of all groundwater withdrawals in Louisiana. MRAA is the major water source to agriculture in the northeastern Louisiana. The groundwater withdrawals from the MRAA increases annually for irrigation. High groundwater pumping has caused significant groundwater level decline and elevated salinity in the aquifer. Therefore, dealing with agricultural irrigation is the primary purpose for managing the MRAA. The main objective of this study is to develop a groundwater model as a tool for the MRAA groundwater management. To do so, a hydrostratigraphy model of the MRAA was constructed by using nearly 8,000 drillers' logs and electric logs collected from Louisiana Department of Natural Resources. The hydrostratigraphy model clearly shows that the Mississippi River cuts into the alluvial aquifer. A grid generation technique was developed to convert the hydrostratigraphy model into a MODFLOW model with 12 layers. A GIS-based method was used to estimate groundwater withdrawals for irrigation wells based on the crop location and acreage from the USDACropScape - Cropland Data Layer. Results from the Variable Infiltration Capacity (VIC) model were used to determine potential recharge. NHDPlusV2 data was used to determine water level for major streams for the MODFLOW River Package. The groundwater model was calibrated using groundwater data between 2004 and 2015 to estimate aquifer hydraulic conductivity, specific yield, specific storage, river conductance, and surficial recharge.

  9. Arsenic in Holocene aquifers of the Red River floodplain, Vietnam: Effects of sediment-water interactions, sediment burial age and groundwater residence time

    Science.gov (United States)

    Sø, Helle Ugilt; Postma, Dieke; , Mai Lan, Vi; Pham, Thi Kim Trang; Kazmierczak, Jolanta; Dao, Viet Nga; Pi, Kunfu; Koch, Christian Bender; Pham, Hung Viet; Jakobsen, Rasmus

    2018-03-01

    Water-sediment interactions were investigated in arsenic contaminated Holocene aquifers of the Red River floodplain, Vietnam, in order to elucidate the origin of the spatial variability in the groundwater arsenic concentration. The investigated aquifers are spread over an 8 × 13 km field area with sediments that varied in burial age from V) redox couple was found in disequilibrium with the other redox couples. Using the pe calculated from the CH4/CO2 redox couple we show that the groundwater has a reducing potential towards Fe-oxides ranging from ferrihydrite to poorly crystalline goethite, but not for well crystalline goethite or hematite. Hematite and poorly crystalline goethite were identified as the Fe-oxides present in the sediments. Reductive dissolution experiments identify two phases releasing Fe(II); one rapidly dissolving that also contains As and a second releasing Fe(II) more slowly but without As. The initial release of Fe and As occurs at a near constant As/Fe ratio that varied from site to site between 1.2 and 0.1 mmol As/mol Fe. Siderite (FeCO3) is the main sink for Fe(II), based on saturation calculations as well as the identification of siderite in the sediment. Most of the carbonate incorporated in siderite originates from the dissolution of sedimentary CaCO3. Over time the CaCO3 content of the sediments diminishes and FeCO3 appears instead. No specific secondary phases that incorporate arsenite could be identified. Alternatively, the amount of arsenic mobilized during the dissolution of reactive phases can be contained in the pool of adsorbed arsenite. Combining groundwater age with aquifer sediment age allows the calculation of the total number of pore volumes flushed through the aquifer. Comparison with groundwater chemistry shows the highest arsenic concentration to be present within the first 200 pore volumes flushed through the aquifer. These results agree with reactive transport modeling combining a kinetic description of reductive

  10. Unsustainability of water resources in the Upper Laja River Basin, Mexico: Social-hydrology interactions in a regional overexploited aquifer with increasing concentrations of fluoride, arsenic and sodium

    Science.gov (United States)

    Ortega, A.

    2013-05-01

    The Upper Laja River Basin, also known as the Independence Basin (IB), with an area of 7,000 km2 and a population near to 500,000 inhabitants is part of the regional Lerma-Chapala Basin in Central Mexico. Groundwater is the main source for drinking water supply, agriculture and industrial uses. Total groundwater extraction is in the order of 1,000 million of m3/a, through near to 3,000 wells in the basin, from which about 85% is for agriculture production, mainly for exportation. Historical hydrologic information in the basin showed the existence of numerous streams, rivers and lakes within the catchments in addition to thousands of springs in the discharge area. At present there is not permanent runoff in the main river and most of the springs and associated ecosystems have disappeared. Water table in the aquifer is between 100 and 200 m depth with decreasing rates between 2 m/a and 10 m/a, while 60 years ago water tables was near ground surface. Dissolved concentration of arsenic and fluoride in groundwater is increasing with time, causing severe health effects in rural villages and more recently in the main urban centers. Increasing concentration of sodium is affecting soil productivity and plant grow, where several hectares of land are been abandoned. There are several pieces of evidence that show the unsustainability of water resources in the IB creating complex social-hydrology interactions: Human actions are impairing the long-term renewability of freshwater stocks and flows. Basic water requirement are not been guaranteed to all inhabitants to maintain human health, neither to restore nor to maintain the remaining ecosystems. Water quality does not meet certain minimum standards in most of the basin. Water-planning and decision making are not democratic, the COTAS, a representation of water users is controlled by farmers with political power; therefore, limiting the participation of other parties and fostering direct participation of affected interests

  11. Ground-water availability from surficial aquifers in the Red River of the North Basin, Minnesota

    Science.gov (United States)

    Reppe, Thomas H.C.

    2005-01-01

    Population growth and commercial and industrial development in the Red River of the North Basin in Minnesota, North Dakota, and South Dakota have prompted the Bureau of Reclamation, U.S. Department of the Interior, to evaluate sources of water to sustain this growth. Nine surficial-glacial (surficial) aquifers (Buffalo, Middle River, Two Rivers, Beach Ridges, Pelican River, Otter Tail, Wadena, Pineland Sands, and Bemidji-Bagley) within the Minnesota part of the basin were identified and evaluated for their ground-water resources. Information was compiled and summarized from published studies to evaluate the availability of ground water. Published information reviewed for each of the aquifers included location and extent, physical characteristics, hydraulic properties, ground-water and surface-water interactions, estimates of water budgets (sources of recharge and discharge) and aquifer storage, theoretical well yields and actual ground-water pumping data, recent (2003) ground-water use data, and baseline ground-water-quality data.

  12. Residence Times in Central Valley Aquifers Recharged by Dammed Rivers

    Science.gov (United States)

    Loustale, M.; Paukert Vankeuren, A. N.; Visser, A.

    2017-12-01

    Groundwater is a vital resource for California, providing between 30-60% of the state's water supply. Recent emphasis on groundwater sustainability has induced a push to characterize recharge rates and residence times for high priority aquifers, including most aquifers in California's Central Valley. Flows in almost all rivers from the western Sierra to the Central Valley are controlled by dams, altering natural flow patterns and recharge to local aquifers. In eastern Sacramento, unconfined and confined shallow aquifers (depth recharged by a losing reach of the Lower American River, despite the presence of levees with slurry cut-off walls.1 Flow in the Lower American River is controlled through the operation of the Folsom and Nimbus Dams, with a minimum flow of 500 cfs. Water table elevation in wells in close proximity to the river are compared to river stage to determine the effect of river stage on groundwater recharge rates. Additionally, Tritium-3Helium dates and stable isotopes (∂18O and ∂2H) have been measured in monitoring wells 200- 2400 ft lateral distance from the river, and depths of 25 -225 feet BGS. Variation in groundwater age in the vertical and horizontal directions are used to determine groundwater flow path and velocity. These data are then used to calculate residence time of groundwater in the unconfined and confined aquifer systems for the Central Valley in eastern Sacramento. Applying groundwater age tracers can benefit future compliance metrics of the California Sustainable Groundwater Resources Act (SGMA), by quantifying river seepage rates and impacts of groundwater management on surface water resources. 1Moran et al., UCRL-TR-203258, 2004.

  13. System-Scale Model of Aquifer, Vadose Zone, and River Interactions for the Hanford 300 Area - Application to Uranium Reactive Transport

    Energy Technology Data Exchange (ETDEWEB)

    Rockhold, Mark L.; Bacon, Diana H.; Freedman, Vicky L.; Parker, Kyle R.; Waichler, Scott R.; Williams, Mark D.

    2013-10-01

    This report represents a synthesis and integration of basic and applied research into a system-scale model of the Hanford 300 Area groundwater uranium plume, supported by the U.S. Department of Energy’s Richland Operations (DOE-RL) office. The report integrates research findings and data from DOE Office of Science (DOE-SC), Office of Environmental Management (DOE-EM), and DOE-RL projects, and from the site remediation and closure contractor, Washington Closure Hanford, LLC (WCH). The three-dimensional, system-scale model addresses water flow and reactive transport of uranium for the coupled vadose zone, unconfined aquifer, and Columbia River shoreline of the Hanford 300 Area. The system-scale model of the 300 Area was developed to be a decision-support tool to evaluate processes of the total system affecting the groundwater uranium plume. The model can also be used to address “what if” questions regarding different remediation endpoints, and to assist in design and evaluation of field remediation efforts. For example, the proposed cleanup plan for the Hanford 300 Area includes removal, treatment, and disposal of contaminated sediments from known waste sites, enhanced attenuation of uranium hot spots in the vadose and periodically rewetted zone, and continued monitoring of groundwater with institutional controls. Illustrative simulations of polyphosphate infiltration were performed to demonstrate the ability of the system-scale model to address these types of questions. The use of this model in conjunction with continued field monitoring is expected to provide a rigorous basis for developing operational strategies for field remediation and for defining defensible remediation endpoints.

  14. Hydrogeologic data for the Big River-Mishnock River stream-aquifer system, central Rhode Island

    Science.gov (United States)

    Craft, P.A.

    2001-01-01

    Hydrogeology, ground-water development alternatives, and water quality in the BigMishnock stream-aquifer system in central Rhode Island are being investigated as part of a long-term cooperative program between the Rhode Island Water Resources Board and the U.S. Geological Survey to evaluate the ground-water resources throughout Rhode Island. The study area includes the Big River drainage basin and that portion of the Mishnock River drainage basin upstream from the Mishnock River at State Route 3. This report presents geologic data and hydrologic and water-quality data for ground and surface water. Ground-water data were collected from July 1996 through September 1998 from a network of observation wells consisting of existing wells and wells installed for this study, which provided a broad distribution of data-collection sites throughout the study area. Streambed piezometers were used to obtain differences in head data between surface-water levels and ground-water levels to help evaluate stream-aquifer interactions throughout the study area. The types of data presented include monthly ground-water levels, average daily ground-water withdrawals, drawdown data from aquifer tests, and water-quality data. Historical water-level data from other wells within the study area also are presented in this report. Surface-water data were obtained from a network consisting of surface-water impoundments, such as ponds and reservoirs, existing and newly established partial-record stream-discharge sites, and synoptic surface-water-quality sites. Water levels were collected monthly from the surface-water impoundments. Stream-discharge measurements were made at partial-record sites to provide measurements of inflow, outflow, and internal flow throughout the study area. Specific conductance was measured monthly at partial-record sites during the study, and also during the fall and spring of 1997 and 1998 at 41 synoptic sites throughout the study area. General geologic data, such as

  15. Potentiometric-surface altitude of the confined aquifer, Wood River Valley aquifer system, south-central Idaho, October 2012.

    Data.gov (United States)

    Department of the Interior — Water levels in 93 wells completed in the Wood River Valley aquifer system were measured during October 22–24, 2012; these wells are part of a network established...

  16. Water-table altitude of the unconfined aquifer, Wood River Valley aquifer system, south-central Idaho, October 2012.

    Data.gov (United States)

    Department of the Interior — Water levels in 93 wells completed in the Wood River Valley aquifer system were measured during October 22–24, 2012; these wells are part of a network established...

  17. Straddle-packer aquifer test analyses of the Snake River Plain aquifer at the Idaho National Engineering Laboratory

    International Nuclear Information System (INIS)

    Johnson, G.S.; Frederick, D.B.

    1997-01-01

    The State of Idaho INEL Oversight Program, with the University of Idaho, Idaho State University, Boise State University, and the Idaho Geologic Survey, used a straddle-packer system to investigate vertical variations in characteristics of the Snake River Plain aquifer at the Idaho National Engineering Laboratory in southeast Idaho. Sixteen single-well aquifer tests were conducted on.isolated intervals in three observation wells. Each of these wells has approximately 200 feet of open borehole below the water table, penetrating the E through G and I basalt flow groups and interbedded sediments of the Snake River Plain aquifer. The success of the aquifer tests was limited by the inability to induce measurable drawdown in several zones. Time-drawdown data from aquifer tests were matched to type curves for 8 of the 16 zones tested. A single aquifer test at the water table exhibited greater curvature than those at depth. The increased degree of curvature suggests an unconfined response and resulted in an estimate of specific yield of 0.03. Aquifer tests below the water table generally yielded time-drawdown graphs with a rapid initial response followed by constant drawdown throughout the duration of the tests; up to several hours in length. The rapid initial response implies that the aquifer responds as a confined system during brief pumping periods. The nearly constant drawdown suggests a secondary source of water, probably vertical flow from overlying and underlying aquifer layers. Three analytical models were applied for comparison to the conceptual model and to provide estimates of aquifer properties. This, Hantush-Jacob leaky aquifer, and the Moench double-porosity fractured rock models were fit to time-drawdown data. The leaky aquifer type curves of Hantush and Jacob generally provided the best match to observed drawdown. A specific capacity regression equation was also used to estimate hydraulic conductivity

  18. Investigating the Sources of Nitrogen Contamination in the Shallow Aquifer of Jakarta using a Newly Developed Distributed River-Aquifer Flow and Transport Model

    Science.gov (United States)

    Costa, D.; Burlando, P.; Liong, S. Y.

    2015-12-01

    Recent observations in the shallow aquifer of Jakarta show a rise in nitrate (NO3-) levels. Groundwater is extensively used in the city to compensate for the limited public water supply network and therefore the risk to public health from a rise in NO3- concentration is high. NO3- has been identified as a cofactor for methemoglobinemia in infants, a disease which can lead to death in extreme cases. The NO3- levels detected are still below regulatory limits for drinking purposes but strategies are necessary to contain the growing problem. To this end, the main sources and pathways of inorganic compounds containing nitrogen (N) - i.e. nitrate, nitrite (NO2-) and ammonium (NH4+) - were investigated. We combined 3 years of field measurements in the Ciliwung River, the major river flowing through Jakarta, with a distributed river-aquifer interaction model to characterize the N-cycle in both systems and quantify the contribution of river infiltration in the overall groundwater N budget. The computed infiltration fluxes were compared to estimates of leaks from poorly maintained septic tanks, which are extensively used in the city, to identify the main source of groundwater contamination. Observations show a strong and interdependent spatial and seasonal variability in the levels of NO3-, NO2- and NH4+ in the river, which is caused by changes in nitrification/denitrification rates due to variations in dissolved oxygen concentrations. Simulation results suggest that such dynamics in the river cause river to aquifer contamination patterns to likewise change over space and time, which leads to heterogeneous vulnerability distributions. The estimated contribution of river-N infiltration to the observed NO3- groundwater levels is small if compared to that originating from all leaking septic tanks inside Jakarta. However, in the vicinity of the Ciliwung, river to groundwater N-loading can play an important role in the local NO3- groundwater levels because it is highly

  19. The effect of river fluctuation frequencies and amplitudes on the extent of the river-aquifer mixing zone and on the dilution of substances

    Science.gov (United States)

    Derx, Julia; Blaschke, Alfred Paul

    2010-05-01

    The river-aquifer mixing zone has been identified in the past by both observations in the field and by applying coupled groundwater models. Its implications are important e.g. for macrozoobenthos or fish eggs, which react sensitively to changes in flow velocities. The groundwater quality is also strongly affected due to the transport of substances from the river into the aquifer and can be altered due to these mixing processes. At a field site east of Vienna, we recently found that the Danube River surface level fluctuations induce circular flow patterns within the mixing zone and cause a greater dispersion of substances dissolved in groundwater. This has possibly important implications for river management, for example, in the case of anthropogenic river level fluctuations. In this paper, we investigate these findings more generally for groundwater-river interaction with different river fluctuation amplitudes and frequencies. We apply an unsaturated-saturated groundwater model and perform an extensive systematic model analysis to identify the effects of river fluctuation frequencies and amplitudes on the extent and location of the mixing zone. Thereby we investigate the influence of the river bank slopes, the hydraulic aquifer properties and the exchange conditions (infiltration and groundwater exfiltration). The estimated extents and locations of the mixing zone are presented for a range of river fluctuation frequencies and amplitudes, for aquifers of high to low permeabilities, for flat and steep riverbanks and for infiltration and groundwater exfiltration. These parameters demonstrate the significant correlation to the extent of the mixing zone and can help to give an estimate for management strategies. Furthermore, we give an overview of how much a non-reactive substance dissolved in groundwater is diluted, due to dispersion within the mixing zone, for the full set of scenarios performed during our systematic model analysis.

  20. Effect of irrigation pumpage during drought on karst aquifer systems in highly agricultural watersheds: example of the Apalachicola-Chattahoochee-Flint river basin, southeastern USA

    Science.gov (United States)

    Mitra, Subhasis; Srivastava, Puneet; Singh, Sarmistha

    2016-09-01

    In the Apalachicola-Chattahoochee-Flint (ACF) river basin in Alabama, Georgia, and Florida (USA), population growth in the city of Atlanta and increased groundwater withdrawal for irrigation in southwest Georgia are greatly affecting the supply of freshwater to downstream regions. This study was conducted to understand and quantify the effect of irrigation pumpage on the karst Upper Floridan Aquifer and river-aquifer interactions in the lower ACF river basin in southwest Georgia. The groundwater MODular Finite-Element model (MODFE) was used for this study. The effect of two drought years, a moderate and a severe drought year, were simulated. Comparison of the results of the irrigated and non-irrigated scenarios showed that groundwater discharge to streams is a major outflow from the aquifer, and irrigation can cause as much as 10 % change in river-aquifer flux. The results also show that during months with high irrigation (e.g., June 2011), storage loss (34 %), the recharge and discharge from the upper semi-confining unit (30 %), and the river-aquifer flux (31 %) are the major water components contributing towards the impact of irrigation pumpage in the study area. A similar scenario plays out in many river basins throughout the world, especially in basins in which underlying karst aquifers are directly connected to a nearby stream. The study suggests that improved groundwater withdrawal strategies using climate forecasts needs to be developed in such a way that excessive withdrawals during droughts can be reduced to protect streams and river flows.

  1. Solute geochemistry of the Snake River Plain regional aquifer system, Idaho and eastern Oregon

    International Nuclear Information System (INIS)

    Wood, W.W.; Low, W.H.

    1987-01-01

    Three geochemical methods were used to determine chemical reactions that control solute concentrations in the Snake River Plain regional aquifer system: (1) calculation of a regional solute balance within the aquifer and of mineralogy in the aquifer framework to identify solute reactions, (2) comparison of thermodynamic mineral saturation indices with plausible solute reactions, and (3) comparison of stable isotope ratios of the groundwater with those in the aquifer framework. The geothermal groundwater system underlying the main aquifer system was examined by calculating thermodynamic mineral saturation indices, stable isotope ratios of geothermal water, geothermometry, and radiocarbon dating. Water budgets, hydrologic arguments, and isotopic analyses for the eastern Snake River Plain aquifer system demonstrate that most, if not all, water is of local meteoric and not juvenile or formation origin. Solute balance, isotopic, mineralogic, and thermodynamic arguments suggest that about 20% of the solutes are derived from reactions with rocks forming the aquifer framework. Reactions controlling solutes in the western Snake river basin are believed to be similar to those in the eastern basin but the regional geothermal system that underlies the Snake river Plain contains total dissolved solids similar to those in the overlying Snake River Plain aquifer system but contains higher concentrations of sodium, bicarbonate, silica, fluoride, sulfate, chloride, arsenic, boron, and lithium, and lower concentrations of calcium, magnesium, and hydrogen. 132 refs., 30 figs., 27 tabs

  2. Hydrochemical Processes in the Alluvial Aquifer of the Gwydir River (Northern New South Wales, Australia)

    OpenAIRE

    Menció, Anna; Mas-Pla, Josep; Korbel, Kathryn; Hose, Grant C.

    2013-01-01

    The hydrochemistry of the Narrabri Formation, the shallow aquifer system of the alluvial fan of the Gwydir River (NSW, Australia), is analyzed to better understand the hydrogeological processes involved in aquifer recharge, and to set up future management options that preserve the quantity and quality of water resources. Results show that groundwater hydrochemistry in this alluvial aquifer is mainly controlled by silicate weathering and cation exchange. However, salt remobilization in specifi...

  3. Ground-water flow directions and estimation of aquifer hydraulic properties in the lower Great Miami River Buried Valley aquifer system, Hamilton Area, Ohio

    Science.gov (United States)

    Sheets, Rodney A.; Bossenbroek, Karen E.

    2005-01-01

    The Great Miami River Buried Valley Aquifer System is one of the most productive sources of potable water in the Midwest, yielding as much as 3,000 gallons per minute to wells. Many water-supply wells tapping this aquifer system are purposely placed near rivers to take advantage of induced infiltration from the rivers. The City of Hamilton's North Well Field consists of 10 wells near the Great Miami River, all completed in the lower Great Miami River Buried Valley Aquifer System. A well-drilling program and a multiple-well aquifer test were done to investigate ground-water flow directions and to estimate aquifer hydraulic properties in the lower part of the Great Miami River Buried Valley Aquifer System. Descriptions of lithology from 10 well borings indicate varying amounts and thickness of clay or till, and therefore, varying levels of potential aquifer confinement. Borings also indicate that the aquifer properties can change dramatically over relatively short distances. Grain-size analyses indicate an average bulk hydraulic conductivity value of aquifer materials of 240 feet per day; the geometric mean of hydraulic conductivity values of aquifer material was 89 feet per day. Median grain sizes of aquifer material and clay units were 1.3 millimeters and 0.1 millimeters, respectively. Water levels in the Hamilton North Well Field are affected by stream stage in the Great Miami River and barometric pressure. Bank storage in response to stream stage is evident. Results from a multiple-well aquifer test at the well field indicate, as do the lithologic descriptions, that the aquifer is semiconfined in some areas and unconfined in others. Transmissivity and storage coefficient of the semiconfined part of the aquifer were 50,000 feet squared per day and 5x10-4, respectively. The average hydraulic conductivity (450 feet per day) based on the aquifer test is reasonable for glacial outwash but is higher than calculated from grain-size analyses, implying a scale effect

  4. Estimation of Hydraulic Parameters and Aquifer Properties for a Managed Aquifer Recharge Pilot Study in The Lower Mississippi River Basin

    Science.gov (United States)

    Ozeren, Y.; Rigby, J.; Holt, R. M.

    2017-12-01

    Mississippi River Valley Alluvial Aquifer (MRVAA) is the major irrigation water resource in the in the lower Mississippi River basin. MRVAA has been significantly depleted in the last two decades due to excessive pumping. A wide range of measures to ensure sustainable groundwater supply in the region is currently under investigation. One of the possible solution under consideration is to use Managed Aquifer Recharge (MAR) by artificial recharge. The proposed artificial recharge technique in this study is to collect water through bank filtration, transfer water via pipeline to the critically low groundwater areas by a set of injection wells. A pilot study in the area is underway to investigate the possibility of artificial recharge in the area. As part of this study, a pumping test was carried out on an existing irrigation well along banks of Tallahatchie River near Money, MS. Geophysical surveys were also carried out in the pilot study area. Hydraulic response of the observation wells was used to determine stream bed conductance and aquifer parameters. The collected hydraulic parameters and aquifer properties will provide inputs for small-scale, high-resolution engineering model for abstraction-injection hydraulics along river. Here, preliminary results of the pilot study is presented.

  5. Appraisal of the surficial aquifers in the Pomme de Terre and Chippewa River Valleys, western Minnesota

    Science.gov (United States)

    Soukup, W.G.; Gillies, D.C.; Myette, C.F.

    1984-01-01

    The surf icial sands in the Pomme de Terre and Chippewa River valleys in Grant, Pope, Stevens, and Swift Counties have been studied to determine the occurrence, availability, and quality of ground water in these aquifers.

  6. To what extent do long-duration high-volume dam releases influence river–aquifer interactions? A case study in New South Wales, Australia

    KAUST Repository

    Graham, Peter W.

    2014-11-20

    Long-duration high-volume dam releases are unique anthropogenic events with no naturally occurring equivalents. The impact from such dam releases on a downstream Quaternary alluvial aquifer in New South Wales, Australia, is assessed. It is observed that long-duration (>26 days), high-volume dam releases (>8,000 ML/day average) result in significant variations in river–aquifer interactions. These variations include a flux from the river to the aquifer up to 6.3 m3/day per metre of bank (at distances of up to 330 m from the river bank), increased extent and volume of recharge/bank storage, and a long-term (>100 days) reversal of river–aquifer fluxes. In contrast, during lower-volume events (<2,000 ML/day average) the flux was directed from the aquifer to the river at rates of up to 1.6 m3/day per metre of bank. A groundwater-head prediction model was constructed and river–aquifer fluxes were calculated; however, predicted fluxes from this method showed poor correlation to fluxes calculated using actual groundwater heads. Long-duration high-volume dam releases have the potential to skew estimates of long-term aquifer resources and detrimentally alter the chemical and physical properties of phreatic aquifers flanking the river. The findings have ramifications for improved integrated management of dam systems and downstream aquifers.

  7. Fate of Arsenic during Red River Water Infiltration into Aquifers beneath Hanoi, Vietnam.

    Science.gov (United States)

    Postma, Dieke; Mai, Nguyen Thi Hoa; Lan, Vi Mai; Trang, Pham Thi Kim; Sø, Helle Ugilt; Nhan, Pham Quy; Larsen, Flemming; Viet, Pham Hung; Jakobsen, Rasmus

    2017-01-17

    Recharge of Red River water into arsenic-contaminated aquifers below Hanoi was investigated. The groundwater age at 40 m depth in the aquifer underlying the river was 1.3 ± 0.8 years, determined by tritium-helium dating. This corresponds to a vertical flow rate into the aquifer of 19 m/year. Electrical conductivity and partial pressure of CO 2 (P CO 2 ) indicate that water recharged from the river is present in both the sandy Holocene and gravelly Pleistocene aquifers and is also abstracted by the pumping station. Infiltrating river water becomes anoxic in the uppermost aquifer due to the oxidation of dissolved organic carbon. Further downward, sedimentary carbon oxidation causes the reduction of As-containing Fe-oxides. Because the release of arsenic by reduction of Fe-oxides is controlled by the reaction rate, arsenic entering the solution becomes highly diluted in the high water flux and contributes little to the groundwater arsenic concentration. Instead, the As concentration in the groundwater of up to 1 μM is due to equilibrium-controlled desorption of arsenic, adsorbed to the sediment before river water started to infiltrate due to municipal pumping. Calculations indicate that it will take several decades of river water infiltration to leach arsenic from the Holocene aquifer to below the World Health Organization limit of 10 μg/L.

  8. Fate of Arsenic during Red River Water Infiltration into Aquifers beneath Hanoi, Vietnam

    Science.gov (United States)

    2016-01-01

    Recharge of Red River water into arsenic-contaminated aquifers below Hanoi was investigated. The groundwater age at 40 m depth in the aquifer underlying the river was 1.3 ± 0.8 years, determined by tritium–helium dating. This corresponds to a vertical flow rate into the aquifer of 19 m/year. Electrical conductivity and partial pressure of CO2 (PCO2) indicate that water recharged from the river is present in both the sandy Holocene and gravelly Pleistocene aquifers and is also abstracted by the pumping station. Infiltrating river water becomes anoxic in the uppermost aquifer due to the oxidation of dissolved organic carbon. Further downward, sedimentary carbon oxidation causes the reduction of As-containing Fe-oxides. Because the release of arsenic by reduction of Fe-oxides is controlled by the reaction rate, arsenic entering the solution becomes highly diluted in the high water flux and contributes little to the groundwater arsenic concentration. Instead, the As concentration in the groundwater of up to 1 μM is due to equilibrium-controlled desorption of arsenic, adsorbed to the sediment before river water started to infiltrate due to municipal pumping. Calculations indicate that it will take several decades of river water infiltration to leach arsenic from the Holocene aquifer to below the World Health Organization limit of 10 μg/L. PMID:27958705

  9. Controlling geological and hydrogeological processes in an arsenic contaminated aquifer on the Red River flood plain, Vietnam

    International Nuclear Information System (INIS)

    Larsen, Flemming; Nhan Quy Pham; Nhan Duc Dang; Postma, Dieke; Jessen, Soren; Viet Hung Pham; Nguyen, Thao Bach; Trieu, Huy Duc; Luu Thi Tran; Hoan Nguyen; Chambon, Julie; Hoan Van Nguyen; Dang Hoang Ha; Nguyen Thi Hue; Mai Thanh Duc; Refsgaard, Jens Christian

    2008-01-01

    Geological and hydrogeological processes controlling recharge and the mobilization of As were investigated in a shallow Holocene aquifer on the Red River flood plain near Hanoi, Vietnam. The geology was investigated using surface resistivity methods, geophysical borehole logging, drilling of boreholes and installation of more than 200 piezometers. Recharge processes and surface-groundwater interaction were studied using (i) time-series of hydraulic head distribution in surface water and aquifers, (ii) the stable isotope composition of waters and (iii) numerical groundwater modeling. The Red River and two of its distributaries run through the field site and control the groundwater flow pattern. For most of the year, there is a regional groundwater flow towards the Red River. During the monsoon the Red River water stage rises up to 6 m and stalls the regional groundwater flow. The two distributaries recharge the aquifer from perched water tables in the dry season, whilst in the flooding period surface water enters the aquifer through highly permeable bank sediments. The result is a dynamic groundwater flow pattern with rapid fluctuations in the groundwater table. A transient numerical model of the groundwater flow yields an average recharge rate of 60-100 mm/a through the confining clay, and a total recharge of approximately 200 mm/a was estimated from 3 H/ 3 He dating of the shallow groundwater. Thus in the model area, recharge of surface water from the river distributaries and recharge through a confining clay is of the same magnitude, being on average around 100 mm/a. The thickness of the confining clay varies between 2 and 10 m, and affects the recharge rate and the transport of electron acceptors (O 2 , NO 3 - and SO 4 2- ) into the aquifer. Where the clay layer is thin, an up to 2 m thick oxic zone develops in the shallow aquifer. In the oxic zone the As concentration is less than 1 μg/L but increases in the reduced zone below to 550 μg/L. In the Holocene

  10. Case studies of groundwater- surface water interactions and scale relationships in small alluvial aquifers

    NARCIS (Netherlands)

    Love, Dave; de Hamer, Wouter; Owen, Richard J.S.; Booij, Martijn J.; Uhlenbrook, Stefan; Hoekstra, Arjen Ysbert; van der Zaag, Pieter

    2007-01-01

    An alluvial aquifer can be described as a groundwater system, generally unconfined, that is hosted in laterally discontinuous layers of gravel, sand, silt and clay, deposited by a river in a river channel, banks or flood plain. In semi-arid regions, streams that are associated with alluvial aquifers

  11. The Importance of Bank Storage in Supplying Baseflow to Rivers Flowing Through Compartmentalized, Alluvial Aquifers

    Science.gov (United States)

    Rhodes, Kimberly A.; Proffitt, Tiffany; Rowley, Taylor; Knappett, Peter S. K.; Montiel, Daniel; Dimova, Natasha; Tebo, Daniel; Miller, Gretchen R.

    2017-12-01

    As water grows scarcer in semiarid and arid regions around the world, new tools are needed to quantify fluxes of water and chemicals between aquifers and rivers. In this study, we quantify the volumetric flux of subsurface water to a 24 km reach of the Brazos River, a lowland river that meanders through the Brazos River Alluvium Aquifer (BRAA), with 8 months of high-frequency differential gaging measurements using fixed gaging stations. Subsurface discharge sources were determined using natural tracers and End-Member Mixing Analysis (EMMA). During a 4 month river stage recession following a high stage event, subsurface discharge decreased from 50 m3/s to 0, releasing a total of 1.0 × 108 m3 of water. Subsurface discharge dried up even as the groundwater table at two locations in the BRAA located 300-500 m from the river remained ˜4 m higher than the river stage. Less than 4% of the water discharged from the subsurface during the prolonged recession period resembled the chemical fingerprint of the alluvial aquifer. Instead, the chemistry of this discharged water closely resembled high stage "event" river water. Together, these findings suggest that the river is well connected to rechargeable bank storage reservoirs but disconnected from the broader alluvial aquifer. The average width of discrete bank storage zones on each side of the river, identified with Electrical Resistivity Tomography (ERT), was approximately 1.5 km. In such highly compartmentalized aquifers, groundwater pumping is unlikely to impact the exchange between the river and the alluvium.

  12. Aquifer depletion in the Lower Mississippi River Basin: challenges and solutions

    Science.gov (United States)

    The Lower Mississippi River Basin (LMRB) is a nationally- and internationally-important region of intensive agricultural production that relies heavily on the underlying Mississippi River Valley Alluvial Aquifer (MRVAA) for row crop irrigation. Extensive irrigation coupled with the region’s geology ...

  13. Benzene dynamics and biodegradation in alluvial aquifers affected by river fluctuations.

    Science.gov (United States)

    Batlle-Aguilar, J; Morasch, B; Hunkeler, D; Brouyère, S

    2014-01-01

    The spatial distribution and temporal dynamics of a benzene plume in an alluvial aquifer strongly affected by river fluctuations was studied. Benzene concentrations, aquifer geochemistry datasets, past river morphology, and benzene degradation rates estimated in situ using stable carbon isotope enrichment were analyzed in concert with aquifer heterogeneity and river fluctuations. Geochemistry data demonstrated that benzene biodegradation was on-going under sulfate reducing conditions. Long-term monitoring of hydraulic heads and characterization of the alluvial aquifer formed the basis of a detailed modeled image of aquifer heterogeneity. Hydraulic conductivity was found to strongly correlate with benzene degradation, indicating that low hydraulic conductivity areas are capable of sustaining benzene anaerobic biodegradation provided the electron acceptor (SO4 (2-) ) does not become rate limiting. Modeling results demonstrated that the groundwater flux direction is reversed on annual basis when the river level rises up to 2 m, thereby forcing the infiltration of oxygenated surface water into the aquifer. The mobilization state of metal trace elements such as Zn, Cd, and As present in the aquifer predominantly depended on the strong potential gradient within the plume. However, infiltration of oxygenated water was found to trigger a change from strongly reducing to oxic conditions near the river, causing mobilization of previously immobile metal species and vice versa. MNA appears to be an appropriate remediation strategy in this type of dynamic environment provided that aquifer characterization and targeted monitoring of redox conditions are adequate and electron acceptors remain available until concentrations of toxic compounds reduce to acceptable levels. © 2013, National Ground Water Association.

  14. Impact of river stage prediction methods on stream-aquifer exchanges in a hydro(geo)logical model at the regional scale

    Science.gov (United States)

    Saleh, F.; Flipo, N.; de Fouquet, C.

    2012-04-01

    for taking into account river stage fluctuations in regional distributed process-based hydro(geo)logical models. It is an efficient way to improve the physics of the stream-aquifer interactions and better assess soil water content at the regional scale when high resolution morphological data is not available. This study offers several perspectives such as simulating the hydrodynamic behavior of alluvial wetlands and assessing the pollutants removal or release by biogeochemical processes at regional scale such as nitrate contamination. Keywords: Stream-aquifer interactions, Regional scale, Quantitative Hydrology, Hydrogeology, River stage simulations, Hydrosystem modeling

  15. Hydraulic properties of the Midville Aquifer at the Savannah River Site, South Carolina

    International Nuclear Information System (INIS)

    Hodges, R.A.; Snipes, D.S.; Benson, S.M.; Daggett, J.S.; Temples, T.; Harrelson, L.

    1994-01-01

    Aquifer performance tests of the Midville Aquifer System were conducted at the Savannah River Site (SRS) in South Carolina. The stratigraphic section of interest consists of Late Cretaceous Coastal Plain sediments. Within the study area, the Midville Aquifer System is composed of sand aquifers separated by discontinuous clay lenses. The Midville is underlain by the Appleton Confining Unit which is separated from underlying Triassic sediments and Paleozoic crystallines by a regional unconformity. This unconformable surface has a dip of 10 m/km to the southeast. The Midville is overlain by the Allendale Confining Unit which separates the Midville from the Dublin Aquifer System. The tests were performed at B and P Areas within the SRS using production wells screened in the Midville Aquifer and monitor well clusters screened in the Midville, Dublin, and Gordon (Eocene) Aquifers. The B Area is located 13 km updip from P Area. The Midville is about 50 meters thick at B Area and 80 meters thick at P Area. The transmissivity of the Midville is 0.0095 m 2 /s at B Area and 0.017 m 2 /s at P Area. The storativity at both areas is about 10 -4 . Vertical leakance of the Midville is greater updip as the stratigraphic section thins. During the B Area test, pumping induced water level changes were detected in aquifers above the Midville. At P Area, no pumping induced water level changes were detected above the Midville Aquifer System

  16. Soil aquifer treatment to remove priority organic pollutants in the Llobregat river area

    OpenAIRE

    Huerta, Maria; Solé, Josep; Aceves, Mercè; Valhondo González, Cristina; Hernández, Marta; Gullón Santos, Martín

    2013-01-01

    The Llobregat River is the main source of water supply in this area. This river together with its aquifer has suffered from several damages which had contributed to endanger a suitable ecological and hydrological status; among them, pollution is a serious problem to deal with. In the last decades, the presence of organic pollutants in this river has been demonstrated [1,2]. Some of them are persistent to biological degradation and have shown to survive wastewater treatments almost unaltered a...

  17. Summary of the Snake River plain Regional Aquifer-System Analysis in Idaho and eastern Oregon

    Science.gov (United States)

    Lindholm, G.F.

    1996-01-01

    Regional aquifers underlying the 15,600-square-mile Snake River Plain in southern Idaho and eastern Oregon was studied as part of the U.S. Geological Survey's Regional Aquifer-System Analysis program. The largest and most productive aquifers in the Snake River Plain are composed of Quaternary basalt of the Snake River Group, which underlies most of the 10,8000-square-mile eastern plain. Aquifer tests and simulation indicate that transmissivity of the upper 200 feet of the basalt aquifer in the eastern plain commonly ranges from about 100,000 to 1,000,000 feet squared per day. However, transmissivity of the total aquifer thickness may be as much as 10 million feet squared per day. Specific yield of the upper 200 feet of the aquifer ranges from about 0.01 to 0.20. Average horizontal hydraulic conductivity of the upper 200 feet of the basalt aquifer ranges from less than 100 to 9,000 feet per day. Values may be one to several orders of magnitude higher in parts in individual flows, such as flow tops. Vertical hydraulic conductivity is probably several orders of magnitude lower than horizontal hydraulic conductivity and is generally related to the number of joints. Pillow lava in ancestral Snake River channels has the highest hydraulic conductivity of all rock types. Hydraulic conductivity of the basalt decreases with depth because of secondary filling of voids with calcite and silica. An estimated 80 to 120 million acre-feet of water is believed to be stored in the upper 200 feet of the basalt aquifer in the eastern plain. The most productive aquifers in the 4,800-square-mile western plain are alluvial sand and gravel in the Boise River valley. Although aquifer tests indicate that transmissivity of alluvium in the Boise River valley ranges from 5,000 to 160,000 feet squared per day, simulation suggests that average transmissivity of the upper 500 feet is generally less than 20,000 feet squared per day. Vertically averaged horizontal hydraulic conductivity of the upper

  18. Surface-Water and Groundwater Interactions along the Withlacoochee River, West-Central Florida

    Science.gov (United States)

    Trommer, J.T.; Yobbi, D.K.; McBride, W.S.

    2009-01-01

    A study of the Withlacoochee River watershed in west-central Florida was conducted from October 2003 to March 2007 to gain a better understanding of the hydrology and surface-water and groundwater interactions along the river. The Withlacoochee River originates in the Green Swamp area in north-central Polk County and flows northerly through seven counties, emptying into the Gulf of Mexico. This study includes only the part of the watershed located between the headwaters in the Green Swamp and the U.S. Geological Survey gaging station near Holder, Florida. The Withlacoochee River within the study area is about 108 miles long and drains about 1,820 square miles. The Withlacoochee River watershed is underlain by thick sequences of carbonate rock that are covered by thin surficial deposits of unconsolidated sand and sandy clay. The clay layer is breached in many places because of the karst nature of the underlying limestone, and the degree of confinement between the Upper Florida aquifer and the surficial aquifer is highly variable throughout the watershed. The potential for movement of water from the surface or shallow deposits to deeper deposits, or from deeper deposits to the shallow deposits, exists throughout the Withlacoochee River watershed. Water levels were higher in deeper Upper Floridan aquifer wells than in shallow Upper Floridan aquifer wells or surficial aquifer wells at 11 of 19 paired or nested well sites, indicating potential for discharge to the surface-water system. Water levels were higher in shallow Upper Floridan aquifer or surficial aquifer wells than in deeper Upper Floridan aquifer wells at five other sites, indicating potential for recharge to the deeper Upper Floridan aquifer. Water levels in the surficial aquifer and Upper Floridan aquifer wells at the remaining three sites were virtually the same, indicating little or no confinement at the sites. Potentiometric-surface maps of the Upper Floridan aquifer indicate the pattern of groundwater

  19. Changes in the water-table altitude of the unconfined aquifer, Wood River Valley aquifer system, south-central Idaho, October 2006 to October 2012.

    Data.gov (United States)

    Department of the Interior — Water levels in 93 wells completed in the Wood River Valley aquifer system were measured during October 22–24, 2012; these wells are part of a network established...

  20. Wells measured for water-levels, unconfined and confined aquifers, Wood River Valley aquifer system, south-central Idaho, October 2006 and October 2012.

    Data.gov (United States)

    Department of the Interior — Water levels in 93 wells completed in the Wood River Valley aquifer system were measured during October 22–24, 2012; these wells are part of a network established...

  1. Changes in the potentiometric-surface altitude of the confined aquifer, Wood River Valley aquifer system, south-central Idaho, October 2006 to October 2012.

    Data.gov (United States)

    Department of the Interior — Water levels in 93 wells completed in the Wood River Valley aquifer system were measured during October 22–24, 2012; these wells are part of a network established...

  2. Estimating the Spatial Extent of Unsaturated Zones in Heterogeneous River-Aquifer Systems

    Science.gov (United States)

    Schilling, Oliver S.; Irvine, Dylan J.; Hendricks Franssen, Harrie-Jan; Brunner, Philip

    2017-12-01

    The presence of unsaturated zones at the river-aquifer interface has large implications on numerous hydraulic and chemical processes. However, the hydrological and geological controls that influence the development of unsaturated zones have so far only been analyzed with simplified conceptualizations of flow processes, or homogeneous conceptualizations of the hydraulic conductivity in either the aquifer or the riverbed. We systematically investigated the influence of heterogeneous structures in both the riverbed and the aquifer on the development of unsaturated zones. A stochastic 1-D criterion that takes both riverbed and aquifer heterogeneity into account was developed using a Monte Carlo sampling technique. The approach allows the reliable estimation of the upper bound of the spatial extent of unsaturated areas underneath a riverbed. Through systematic numerical modeling experiments, we furthermore show that horizontal capillary forces can reduce the spatial extent of unsaturated zones under clogged areas. This analysis shows how the spatial structure of clogging layers and aquifers influence the propensity for unsaturated zones to develop: In riverbeds where clogged areas are made up of many small, spatially disconnected patches with a diameter in the order of 1 m, unsaturated areas are less likely to develop compared to riverbeds where large clogged areas exist adjacent to unclogged areas. A combination of the stochastic 1-D criterion with an analysis of the spatial structure of the clogging layers and the potential for resaturation can help develop an appropriate conceptual model and inform the choice of a suitable numerical simulator for river-aquifer systems.

  3. River infiltration to a subtropical alluvial aquifer inferred using multiple environmental tracers

    Science.gov (United States)

    Lamontagne, S.; Taylor, A. R.; Batlle-Aguilar, J.; Suckow, A.; Cook, P. G.; Smith, S. D.; Morgenstern, U.; Stewart, M. K.

    2015-06-01

    Chloride (Cl-), stable isotope ratios of water (δ18O and δ2H), sulfur hexafluoride (SF6), tritium (3H), carbon-14 (14C), noble gases (4He, Ne, and Ar), and hydrometry were used to characterize groundwater-surface water interactions, in particular infiltration rates, for the Lower Namoi River (New South Wales, Australia). The study period (four sampling campaigns between November 2009 and November 2011) represented the end of a decade-long drought followed by several high-flow events. The hydrometry showed that the river was generally losing to the alluvium, except when storm-derived floodwaves in the river channel generated bank recharge—discharge cycles. Using 3H/14C-derived estimates of groundwater mean residence time along the transect, infiltration rates ranged from 0.6 to 5 m yr-1. However, when using the peak transition age (a more realistic estimate of travel time in highly dispersive environments), the range in infiltration rate was larger (4-270 m yr-1). Both river water (highest δ2H, δ18O, SF6, 3H, and 14C) and an older groundwater source (lowest δ2H, δ18O, SF6, 3H, 14C, and highest 4He) were found in the riparian zone. This old groundwater end-member may represent leakage from an underlying confined aquifer (Great Artesian Basin). Environmental tracers may be used to estimate infiltration rates in this riparian environment but the presence of multiple sources of water and a high dispersion induced by frequent variations in the water table complicates their interpretation.

  4. Aquifers

    Data.gov (United States)

    Earth Data Analysis Center, University of New Mexico — This map layer contains the shallowest principal aquifers of the conterminous United States, Hawaii, Puerto Rico, and the U.S. Virgin Islands, portrayed as polygons....

  5. Distribution of polychlorinated biphenyls in the Housatonic River and adjacent aquifer, Massachusetts

    Science.gov (United States)

    Gay, Frederick B.; Frimpter, Michael H.

    1985-01-01

    Polychlorinated biphenyls (PCB's) are sorbed to the fine-grained stream-bottom sediments along the Housatonic River from Pittsfield, Massachusetts, southward to the Massachusetts-Connecticut boundary. The highest PCB concentrations, up to 140,000 micrograms per kilogram, were found in samples of bottom material from a reach of the river between Pittsfield and Woods Pond Dam in Lee, Massachusetts. Sediments in Woods Pond have been estimated to contain about 11,000 pounds of PCB's. Approximately 490 pounds per year of PCB's have also been estimated to move past the Housatonic River gaging station at Great Barrington. The distribution of hydraulic heads, water temperatures, and concentrations of dissolved oxygen, ammonia, nitrate, iron, and manganese in ground water shows that industrial water-supply wells in a sand and gravel aquifer adjacent to a stretch of the river called Woods Pond have been inducing ground-water recharge through the PCB-contaminated bottom sediments of the pond since late 1956. These data indicate that, at one location along the shore of the pond, the upper 40 feet of the aquifer contains water derived from induced infiltration. However, this induced recharge has not moved PCB's from the bottom sediments into a vertical section of the aquifer located 5 feet downgradient from the edge of Woods Pond. Samples taken at selected intervals in this section showed that no PCB's sorbed to the aquifer material or dissolved in the ground water within the detection limits of the chemical analyses.

  6. New Module to Simulate Groundwater-Surface Water Interactions in Small-Scale Alluvial Aquifer System.

    Science.gov (United States)

    Flores, L.

    2017-12-01

    Streamflow depletion can occur when groundwater pumping wells lower water table elevations adjacent to a nearby stream. Being able to accurately model the severity of this process is of critical importance in semi-arid regions where groundwater-surface water interactions affect water rights and the sustainability of water resource practices. The finite-difference flow model MODFLOW is currently the standard for estimating groundwater-surface water interactions in many regions in the western United States. However, certain limitations of the model persist when highly-resolved spatial scales are used to represent the stream-aquifer system, e.g. when the size of computational grid cells is much less than the river width. In this study, an external module is developed and linked with MODFLOW that (1) allows for multiple computational grid cells over the width of the river; (2) computes streamflow and stream stage along the length of the river using the one-dimensional (1D) steady (over a stress period) shallow water equations, which allows for more accurate stream stages when normal flow cannot be assumed or a rating curve is not available; and (3) incorporates a process for computing streamflow loss when an unsaturated zone develops under the streambed. Use of the module not only provides highly-resolved estimates of streamflow depletion, but also of streambed hydraulic conductivity. The new module is applied to the stream-aquifer alluvial system along the South Platte River south of Denver, Colorado, with results tested against field-measured groundwater levels, streamflow, and streamflow depletion.

  7. River Intrusion in Karst Springs in Eogenetic Aquifers: Implications for Speleogenesis

    Science.gov (United States)

    Martin, J. B.; Gulley, J.; Screaton, E. J.

    2008-12-01

    Conceptual models of speleogenesis generally assume uni-directional transport in integrated conduit systems from discrete recharge points to discharge at karst springs. Estavelles, however, are karst springs that function intermittently as discrete recharge points when river stage rises more rapidly than local aquifer heads. As river water chemistry changes between baseflow and floods, estavelles should influence mass transport through (e.g. organic carbon, nutrients, and oxygen) and speleogenesis within karst systems. Estavelles are common in our study area in north-central Florida, particularly along the lower reaches of the Santa Fe River, where it flows across the unconfined karstic Floridan aquifer. River stage in this unconfined region can rise much faster than aquifer heads when large amounts of rain fall on the confined regions in its upper reaches. Backflooding into the estavelles during elevated river stage drives river water into the ground, causing some springs to reverse and other springs to recirculate large volumes of river water. Floodwaters originating in the confined region are highly undersaturated with respect to calcite, and thus river water transitions from slightly supersaturated to highly undersaturated with respect to calcite during flood events. As a result, conduits connected to estavelles are continuously enlarged as springs reverse or recirculate calcite-undersaturated river water. It has been suggested that currently flooded caves (i.e. karst conduits) associated with springs in Florida formed entirely underwater because speleothems, which are prevalent in flooded caves in the Yucatan and Bahamas, have not been observed by cave divers. Results of this study indicate that the absence of speleothems does not necessarily provide evidence of a continuous phreatic history for underwater caves. Instead speleothems that formed in caves while dry could have been dissolved by backflooding of estavelles with undersaturated water

  8. Geohydrology and water quality of the North Platte River alluvial aquifer, Garden County, Western Nebraska

    Science.gov (United States)

    Steele, Gregory V.; Cannia, James C.

    1995-01-01

    In 1993, a 3-year study was begun to describe the geohydrology and water quality of the North Platte River alluvial aquifer near Oshkosh, Garden County, Nebraska. The study's objectives are to evaluate the geohydrologic characteristics of the alluvial aquifer and to establish a network of observation wells for long-term monitoring of temporal variations and spatial distributions of nitrate and major-ion concentrations. Monitor wells were installed at 11 sites near Oshkosh. The geohydrology of the aquifer was characterized based on water-level measurements and two short-term aquifer tests. Bimonthly water samples were collected and analyzed for pH, specific conductivity, water temperature, dissolved oxygen, and nutrients that included dissolved nitrate. Concentrations of major ions were defined from analyses of semiannual water samples. Analyses of the geohydrologic and water-quality data indicate that the aquifer is vulnerable to nitrate contamination. These data also show that nitrate concentrations in ground water flowing into and out of the study area are less than the U.S. Environmental Protection Agency's Maximum Concentration Level of 10 milligrams per liter for drinking water. Ground water from Lost Creek Valley may be mixing with ground water in the North Platte River Valley, somewhat moderating nitrate concentrations near Oshkosh.

  9. Evaluation of aquifer heterogeneity effects on river flow loss using a transition probability framework

    Science.gov (United States)

    Engdahl, N.B.; Vogler, E.T.; Weissmann, G.S.

    2010-01-01

    River-aquifer exchange is considered within a transition probability framework along the Rio Grande in Albuquerque, New Mexico, to provide a stochastic estimate of aquifer heterogeneity and river loss. Six plausible hydrofacies configurations were determined using categorized drill core and wetland survey data processed through the TPROGS geostatistical package. A base case homogeneous model was also constructed for comparison. River loss was simulated for low, moderate, and high Rio Grande stages and several different riverside drain stage configurations. Heterogeneity effects were quantified by determining the mean and variance of the K field for each realization compared to the root-mean-square (RMS) error of the observed groundwater head data. Simulation results showed that the heterogeneous models produced smaller estimates of loss than the homogeneous approximation. Differences between heterogeneous and homogeneous model results indicate that the use of a homogeneous K in a regional-scale model may result in an overestimation of loss but comparable RMS error. We find that the simulated river loss is dependent on the aquifer structure and is most sensitive to the volumetric proportion of fines within the river channel. Copyright 2010 by the American Geophysical Union.

  10. Hydrogeology of the Ramapo River-Woodbury Creek valley-fill aquifer system and adjacent areas in eastern Orange County, New York

    Science.gov (United States)

    Heisig, Paul M.

    2015-01-01

    The hydrogeology of the valley-fill aquifer system and surrounding watershed areas was investigated within a 23-mile long, fault-controlled valley in eastern Orange County, New York. Glacial deposits form a divide within the valley that is drained to the north by Woodbury Creek and is drained to the south by the Ramapo River. Surficial geology, extent and saturated thickness of sand and gravel aquifers, extent of confining units, bedrock-surface elevation beneath valleys, major lineaments, and the locations of wells for which records are available were delineated on an interactive map.

  11. A Microbiological Water Quality Evaluation of Ganges River Deltaic Aquifers

    Science.gov (United States)

    Yerby, C. J.; Gragg, S. E.; Page, J.; Leavens, J.; Bhattacharya, P.; Harrington, J.; Datta, S.

    2014-12-01

    Substantial natural contamination from trace elements (like arsenic) and pathogens make Ganges Deltaic aquifers an area of utmost concern. Following millions of cases of chronic arsenic poisoning from the groundwaters of the region, numerous residents are still knowingly ingesting water from shallow to intermediate accessible depth drinking water wells. Added to the calamity of arsenic is the prevalence of pathogenic bacteria in these waters. The increasing frequency of gastroenteritis signifies the need to quantify the magnitude and extensiveness of health degrading agents--bacterial pathogens (i.e. Salmonella) and non-pathogens (i.e. Enterobacteriaceae) --within the water supply in accessible Gangetic aquifers. To assess the dissolved microbiological quality in the region, present study sampling locations are along defined piezometer nests in an area in SE Asia (Bangladesh). Every nest contains samples from wells at varying depths covering shallow to deep aquifers. To date, 17 of the 76 water samples were analyzed for Salmonella, generic Escherichia coli (E. coli) and coliforms. Briefly, samples were plated in duplicate onto E. coli/Coliform petrifilm and incubated at 370C for 48 hours. Next, each sample was enriched in buffered peptone water and incubated at 370C for 18 hours. Bacterial DNA was extracted and amplified using a qPCR machine. Amplification plots were analyzed to determine presence/absence of microorganisms. All water samples (n=~76) are analyzed for Salmonella, Escherichia coli O157:H7, Listeria spp. and Shigella. Pathogen populations of PCR-positive water samples are enumerated using the agar direct plate method. Non-pathogenic bacterial indicator organisms (i.e. Enterobacteriaceae) will also be enumerated. Over the course of the experiment, we hypothesize that shallower wells will 1)have a higher pathogen prevalence and 2)harbor pathogens and nonpathogens at higher concentrations. While the 17 samples analyzed to date were negative for Salmonella

  12. Simulated effects of groundwater withdrawals from the Kirkwood-Cohansey aquifer system and Piney Point aquifer, Maurice and Cohansey River Basins, Cumberland County and vicinity, New Jersey

    Science.gov (United States)

    Gordon, Alison D.; Buxton, Debra E.

    2018-05-10

    The U.S. Geological Survey, in cooperation with the New Jersey Department of Environmental Protection, conducted a study to simulate the effects of withdrawals from the Kirkwood-Cohansey aquifer system on streamflow and groundwater flow and from the Piney Point aquifer on water levels in the Cohansey and Maurice River Basins in Cumberland County and surrounding areas. The aquifer system consists of gravel, sand, silt, and clay sediments of the Cohansey Sand and Kirkwood Formation that dip and thicken to the southeast. The aquifer system is generally an unconfined aquifer, but semi-confined and confined conditions exist within the Cumberland County study area. The Kirkwood-Cohansey aquifer system is present throughout Cumberland County and is the principal source of groundwater for public, domestic, agricultural-irrigation, industrial, and commercial water uses. In 2008, reported groundwater withdrawals from the Kirkwood-Cohansey aquifer system in the study area totaled about 21,700 million gallons—about 36 percent for public supply; about 49 percent for agricultural irrigation; and about 15 percent for industrial, commercial, mining by sand and gravel companies, and non-agricultural irrigation uses. A transient numerical groundwater-flow model of the Kirkwood-Cohansey aquifer system was developed and calibrated by incorporating monthly recharge, base-flow estimates, water-level data, surface-water diversions and discharges, and groundwater withdrawals from 1998 to 2008.The groundwater-flow model was used to simulate five withdrawal scenarios to observe the effects of additional groundwater withdrawals on the Kirkwood-Cohansey aquifer system and streams. These scenarios include (1) average 1998 to 2008 monthly groundwater withdrawals (baseline scenario); (2) monthly full-allocation groundwater withdrawals, but agricultural-irrigation withdrawals were decreased for October through March; (3) monthly full-allocation groundwater withdrawals; (4) estimated monthly

  13. Numerical simulation of groundwater flow for the Yakima River basin aquifer system, Washington

    Science.gov (United States)

    Ely, D.M.; Bachmann, M.P.; Vaccaro, J.J.

    2011-01-01

    A regional, three-dimensional, transient numerical model of groundwater flow was constructed for the Yakima River basin aquifer system to better understand the groundwater-flow system and its relation to surface-water resources. The model described in this report can be used as a tool by water-management agencies and other stakeholders to quantitatively evaluate proposed alternative management strategies that consider the interrelation between groundwater availability and surface-water resources.

  14. Inference of Stream Network Fragmentation Patterns from Ground Water - Surface Water Interactions on the High Plains Aquifer

    Science.gov (United States)

    Chandler, D. G.; Yang, X.; Steward, D. R.; Gido, K.

    2007-12-01

    Stream networks in the Great Plains integrate fluxes from precipitation as surface runoff in discrete events and groundwater as base flow. Changes in land cover and agronomic practices and development of ground water resources to support irrigated agriculture have resulted in profound changes in the occurrence and magnitude of stream flows, especially near the Ogallala aquifer, where precipitation is low. These changes have demonstrably altered the aquatic habitat of western Kansas, with documented changes in fish populations, riparian communities and groundwater quality due to stream transmission losses. Forecasting future changes in aquatic and riparian ecology and groundwater quality requires a large scale spatially explicit model of groundwater- surface water interaction. In this study, we combine historical data on land use, stream flow, production well development and groundwater level observations with groundwater elevation modeling to support a geospatial framework for assessing changes in refugia for aquatic species in four rivers in western Kansas between 1965 and 2005. Decreased frequency and duration of streamflow occurred in all rivers, but the extent of change depended on the geomorphology of the river basin and the extent of groundwater development. In the absence of streamflow, refugia for aquatic species were defined as the stream reaches below the phreatic surface of the regional aquifer. Changes in extent, location and degree of fragmentation of gaining reaches was found to be a strong predictor of surface water occurrence during drought and a robust hydrological template for the analysis of changes in recharge to alluvial and regional aquifers and riparian and aquatic habitat.

  15. Potentiometric Surface of the Upper Floridan Aquifer in the St. Johns River Water Management District and Vicinity, Florida, May 2009

    Science.gov (United States)

    Kinnaman, Sandra L.; Dixon, Joann F.

    2009-01-01

    This map depicts the potentiometric surface of the Upper Floridan aquifer in the St. Johns River Water Management District and vicinity for May 2009. Potentiometric contours are based on water-level measurements collected at 625 wells during the period May 14 - May 29, near the end of the dry season. Some contours are inferred from previous potentiometric-surface maps with larger well networks. The potentiometric surface of the carbonate Upper Floridan aquifer responds mainly to rainfall, and more locally, to groundwater withdrawals and spring flow. Potentiometric-surface highs generally correspond to topographic highs where the aquifer is recharged. Springs and areas of diffuse upward leakage naturally discharge water from the aquifer and are most prevalent along the St. Johns River. Areas of discharge are reflected by depressions in the potentiometric surface. Groundwater withdrawals locally have lowered the potentiometric surface. Groundwater in the Upper Floridan aquifer generally flows from potentiometric highs to potentiometric lows in a direction perpendicular to the contours.

  16. Potentiometric Surface of the Upper Floridan Aquifer in the St. Johns River Water Management District and Vicinity, Florida, May 2005

    Science.gov (United States)

    Kinnaman, Sandra L.

    2006-01-01

    INTRODUCTION This map depicts the potentiometric surface of the upper Floridan aquifer in the St. Johns River Water Management District and vicinity for May 2005. Potentiometric contours are based on water level measurements collected at 598 wens during the period May 5 - 31, near the end of the dry season. Some contours are inferred from previous potentiometric-surface maps with larger well networks. The potentiometric surface of the carbonate upper Floridan aquifer responds mainly to rainfall, and more locally, to ground water withdrawals. Potentiometric-surface highs generally correspond to topographic highs where the aquifer is recharged. Springs and areas of diffuse upward leakage naturally discharge water from the aquifer and are most prevalent along the St. Johns River. Areas of discharge are reflected by depressions in the potentiometric surface. Ground water withdrawals locally have lowered the potentiometric surface. Ground water in the upper Floridan aquifer generally flows from potentiometric highs to potentiometric lows in a direction perpendicular to the contours.

  17. Vegetation dynamics induced by phreatophyte--aquifer interactions.

    Science.gov (United States)

    Ridolfi, Luca; D'Odorico, Paolo; Laio, Francesco

    2007-09-21

    The dynamics of phreatophyte vegetation are strongly coupled to those of the shallow phreatic aquifers from which phreatophytes extract water. Vegetation is able to influence the depth of the water table, which, in turn, can induce stress in vegetation. These interactions are likely to affect the composition and structure of phreatophyte plant communities, as well as their successional dynamics. Despite the environmental and economical value of many wetland plant ecosystems around the world, the impact of vegetation-water table interactions on ecosystem succession and interspecies competition in phreatophyte plant communities remains poorly understood. This study develops a minimalistic modelling framework to investigate the dynamics of two phreatophyte species, and their interactions with the water table. In spite of its simplicity, the model exhibits a remarkable variety of dynamical behaviors, especially when the water table depth is forced by external drivers. It is shown that, even when one of the two species is dominant with respect to the other, these two species can coexist showing periodic, quasi-periodic, and chaotic dynamics. Moreover, in the presence of a random environmental forcing, noise-induced coexistence may emerge.

  18. Flow of river water into a Karstic limestone aquifer. 1. Tracing the young fraction in groundwater mixtures in the Upper Floridan Aquifer near Valdosta, Georgia

    International Nuclear Information System (INIS)

    Plummer, L.N.; Busenberg, E.; McConnell, J.B.; Drenkard, S.; Schlosser, P.; Michel, R.L.

    1998-01-01

    The quality of water in the Upper Floridan aquifer near Valdosta, Georgia is affected locally by discharge of Withlacoochee River water through sinkholes in the river bed. Data on transient tracers and other dissolved substances, including Cl - , 3 H, tritiogenic helium-3 ( 3 He), chlorofluorocarbons (CFC-11, CFC-12, CFC-113), organic C (DOC), O 2 (DO), H 2 S, CH 4 , δ 18 O, δD, and 14 C were investigated as tracers of Withlacoochee River water in the Upper Floridan aquifer. The concentrations of all tracers were affected by dilution and mixing. Dissolved Cl - , δ 18 O, δD, CFC-12, and the quantity ( 3 H+ 3 He) are stable in water from the Upper Floridan aquifer, whereas DOC, DO, H 2 S, CH 4 , 14 C, CFC-11, and CFC-113 are affected by microbial degradation and other geochemical processes occurring within the aquifer. Groundwater mixing fractions were determined by using dissolved Cl - and δ 18 O data, recognizing 3 end-member water types in the groundwater mixtures: (1) Withlacoochee River water (δ 18 O=-2.5±0.3per thousand, Cl - =12.2±2 mg/l), (2) regional infiltration water (δ 18 O=-4.2±0.1per thousand, Cl - =2.3±0.1 mg/l), and (3) regional paleowater resident in the Upper Floridan aquifer (δ 18 O=-3.4±0.1per thousand, Cl - =2.6±0.1 mg/l) (uncertainties are ±1σ). Error simulation procedures were used to define uncertainties in mixing fractions. Fractions of river water in groundwater range from 0 to 72% and average 10%. The influence of river-water discharge on the quality of water in the Upper Floridan aquifer was traced from the sinkhole area on the Withlacoochee River 25 km SE in the direction of regional groundwater flow. Infiltration of water is most significant to the N and NW of Valdosta, but becomes negligible to the S and SE in the direction of general thickening of post-Eocene confining beds overlying the Upper Floridan aquifer. (Copyright (c) 1998 Elsevier Science B.V., Amsterdam. All rights reserved.)

  19. Flow of river water into a Karstic limestone aquifer. 1. Tracing the young fraction in groundwater mixtures in the Upper Floridan Aquifer near Valdosta, Georgia

    Energy Technology Data Exchange (ETDEWEB)

    Plummer, L.N.; Busenberg, E. [U.S. Geological Survey, 432 National Center, Reston, VA (United States); McConnell, J.B. [U.S. Geological Survey, 3039 Amwiler Rd., Atlanta, GA (United States); Drenkard, S.; Schlosser, P. [Lamont-Doherty Earth Observatory of Columbia University, 61 Route 9W, Palisades, NY (United States); Michel, R.L. [U.S. Geological Survey, Mail Stop 434, 345 Middlefield Road, Menlo Park, CA (United States)

    1998-11-01

    he quality of water in the Upper Floridan aquifer near Valdosta, Georgia is affected locally by discharge of Withlacoochee River water through sinkholes in the river bed. Data on transient tracers and other dissolved substances, including Cl{sup -}, {sup 3}H, tritiogenic helium-3 ({sup 3}He), chlorofluorocarbons (CFC-11, CFC-12, CFC-113), organic C (DOC), O{sub 2} (DO), H{sub 2}S, CH{sub 4}, {delta}{sup 18}O, {delta}D, and {sup 14}C were investigated as tracers of Withlacoochee River water in the Upper Floridan aquifer. The concentrations of all tracers were affected by dilution and mixing. Dissolved Cl{sup -}, {delta}{sup 18}O, {delta}D, CFC-12, and the quantity ({sup 3}H+{sup 3}He) are stable in water from the Upper Floridan aquifer, whereas DOC, DO, H{sub 2}S, CH{sub 4}, {sup 14}C, CFC-11, and CFC-113 are affected by microbial degradation and other geochemical processes occurring within the aquifer. Groundwater mixing fractions were determined by using dissolved Cl{sup -} and {delta}{sup 18}O data, recognizing 3 end-member water types in the groundwater mixtures: (1) Withlacoochee River water ({delta}{sup 18}O=-2.5{+-}0.3per thousand, Cl{sup -}=12.2{+-}2 mg/l), (2) regional infiltration water ({delta}{sup 18}O=-4.2{+-}0.1per thousand, Cl{sup -}=2.3{+-}0.1 mg/l), and (3) regional paleowater resident in the Upper Floridan aquifer ({delta}{sup 18}O=-3.4{+-}0.1per thousand, Cl{sup -}=2.6{+-}0.1 mg/l) (uncertainties are {+-}1{sigma}). Error simulation procedures were used to define uncertainties in mixing fractions. Fractions of river water in groundwater range from 0 to 72% and average 10%. The influence of river-water discharge on the quality of water in the Upper Floridan aquifer was traced from the sinkhole area on the Withlacoochee River 25 km SE in the direction of regional groundwater flow. Infiltration of water is most significant to theN and NW of Valdosta, but becomes negligible to the S and SE in the direction of general thickening of post-Eocene confining

  20. Preliminary survey of the vulnerability to the contamination of the aquifers of Morondava river catchments

    International Nuclear Information System (INIS)

    Randrianasolo, A.F.

    2004-01-01

    The objective of this work is to make a preliminary survey of the vulnerability to the contamination of the aquifers of Morondava river catchments. The methods used are the geological and hydrogeological surveys, the hydrochemistry and isotopic techniques. This survey allows us to have an overview of the chemical features of groundwaters, conditions of recharge, and especially to determine the potential and active zone of nitrate pollution. Two field works have been carried out within the frame of MAG/8/003 project. The first one is focused on groundwater sampling and surface water sampling, and the second one is based on the geological and hydrogeological surveys. The samples were sent for isotope ( 18 O, 2 H, 15 N, 87 Sr, 3 H) and chemical analysis to the I.A.E.A laboratories. The survey gave the following conclusions: the groundwaters are affected by evaporation before or during infiltration and saline intrusion. The region of Morondava is submitted to a regime of simple oceanic precipitation (excess in deuterium). The boreholes waters is of sodic-bicarbonate chemical type, whereas well waters belong to the calcic-bicarbonate. The superficial aquifers (subsurface water) trapped by the wells are more vulnerable than deep aquifers (homogeneous aquifers) trapped by boreholes. These hypotheses are proven by geological and hydrogeological investigations, by the groundwaters nitrate analyses results, and are confirmed by radioactive isotope. [fr

  1. Hydrogeologic framework of the uppermost principal aquifer systems in the Williston and Powder River structural basins, United States and Canada

    Science.gov (United States)

    Thamke, Joanna N.; LeCain, Gary D.; Ryter, Derek W.; Sando, Roy; Long, Andrew J.

    2014-01-01

    The glacial, lower Tertiary, and Upper Cretaceous aquifer systems in the Williston and Powder River structural basins within the United States and Canada are the uppermost principal aquifer systems and most accessible sources of groundwater for these energy-producing basins. The glacial aquifer system covers the northeastern part of the Williston structural basin. The lower Tertiary and Upper Cretaceous aquifer systems are present in about 91,300 square miles (mi2) of the Williston structural basin and about 25,500 mi2 of the Powder River structural basin. Directly under these aquifer systems are 800 to more than 3,000 feet (ft) of relatively impermeable marine shale that serves as a basal confining unit. The aquifer systems in the Williston structural basin have a shallow (less than 2,900 ft deep), wide, and generally symmetrical bowl shape. The aquifer systems in the Powder River structural basin have a very deep (as much as 8,500 ft deep), narrow, and asymmetrical shape.

  2. Quantification of River Nile/Quaternary aquifer exchanges via ...

    Indian Academy of Sciences (India)

    3Civil Engineering Department, Minia University, Minia, Egypt. ∗ ... This study approach seeks to characterize the hydraulic interactions .... organic compounds are the most common oxidiz- .... Nile and applied irrigation, subsurface drainage.

  3. Flow of river water into a karstic limestone aquifer-2. Dating the young fraction in groundwater mixtures in the Upper Floridan aquifer near Valdosta, Georgia

    International Nuclear Information System (INIS)

    Plummer, L.N.; Busenberg, E.; Drenkard, S.; Schlosser, P.; Ekwurzel, B.; Weppernig, R.; McConnell, J.B.; Michel, R.L.

    1998-01-01

    Tritium/helium-3 ( 3 H/ 3 He) and chlorofluorocarbon (CFCs, CFC-11, CFC-12, CFC-113) data are used to date the young fraction in groundwater mixtures from a karstic limestone aquifer near Valdosta, Georgia, where regional paleowater in the Upper Floridan aquifer receives recharge from two young sources-the flow of Withlacoochee River water through sinkholes in the river bed, and leakage of infiltration water through post-Eocene semi-confining beds above the Upper Floridan aquifer. In dating the young fraction of mixtures using CFCs, it is necessary to reconstruct the CFC concentration that was in the young fraction prior to mixing. The 3 H/ 3 He age is independent of the extent of dilution with older ( 3 H-free and 3 He trit -free) water. The groundwater mixtures are designated as Type-1 for mixtures of regional paleowater and regional infiltration water and Type-2 for mixtures containing more than approximately 4% of river water. The fractions of regional paleowater, regional infiltration water, and Withlacoochee River water in the groundwater mixtures were determined from Cl - and δ 18 O data for water from the Upper Floridan aquifer at Valdosta, Georgia.The chlorofluorocarbons CFC-11 and CFC-113 are removed by microbial degradation and/or sorption processes in most anaerobic (Type-2) groundwater at Valdosta, but are present in some aerobic Type-1 water. CFC-12 persists in both SO 4 -reducing and methanogenic water. The very low detection limits for CFCs (approximately 0.3 pg kg -1 ) permitted CFC-11 and CFC-12 dating of the fraction of regional infiltration water in Type-1 mixtures, and CFC-12 dating of the river-water fraction in Type-2 mixtures. Overall, approximately 50% of the 85 water samples obtained from the Upper Floridan aquifer have CFC-12-based ages of the young fraction that are consistent with the 3 H concentration of the groundwater. Because of uncertainties associated with very low 3 H and 3 He content in dilute mixtures, 3 H/ 3 He dating is

  4. Flow of river water into a karstic limestone aquifer - 2. Dating the young fraction in groundwater mixtures in the Upper Floridan aquifer near Valdosta, Georgia

    Science.gov (United States)

    Plummer, Niel; Busenberg, E.; Drenkard, S.; Schlosser, P.; Ekwurzel, B.; Weppernig, R.; McConnell, J.B.; Michel, R.L.

    1998-01-01

    Tritium/helium-3 (3H/3He) and chlorofluorocarbon (CFCs, CFC-11, CFC-12, CFC-113) data are used to date the young fraction in groundwater mixtures from a karstic limestone aquifer near Valdosta, Georgia, where regional paleowater in the Upper Floridan aquifer receives recharge from two young sources the flow of Withlacoochee River water through sinkholes in the river bed, and leakage of infiltration water through post-Eocene semi-confining beds above the Upper Floridan aquifer. In dating the young fraction of mixtures using CFCs, it is necessary to reconstruct the CFC concentration that was in the young fraction prior to mixing. The 3H/3He age is independent of the extent of dilution with older (3H-free and 3He(trit)-free) water. The groundwater mixtures are designated as Type-I for mixtures of regional paleowater and regional infiltration water and Type-2 for mixtures containing more than approximately 4% of river water. The fractions of regional paleowater, regional infiltration water, and Withlacoochee River water in the groundwater mixtures were determined from Cl- and ??18O data for water from the Upper Floridan aquifer at Valdosta, Georgia The chlorofluorocarbons CFC-11 and CFC-113 are removed by microbial degradation and/or sorption processes in most allaerobic (Type-2) groundwater at Valdosta, but are present in some aerobic Type-I water. CFC-12 persists in both SO4-reducing and methanogenic water. The very low detection limits for CFCs (approximately 0.3 pg kg-1) permitted CFC-11 and CFC-12 dating of the fraction of regional infiltration water in Type-I mixtures, and CFC-12 dating of the river-water fraction in Type-2 mixtures. Overall, approximately 50% of the 85 water sam pies obtained from the Upper Floridan aquifer have CFC-12-based ages of the young traction that are consistent with the 3H concentration of the groundwater. Because of uncertainties associated with very low 3H and 3He content in dilute mixtures, 3H/3He dating is limited to the river

  5. Radionuclides as natural tracers of the interaction between groundwater and surface water in the River Andarax, Spain.

    Science.gov (United States)

    Navarro-Martinez, Francisco; Salas Garcia, Alejandro; Sánchez-Martos, Francisco; Baeza Espasa, Antonio; Molina Sánchez, Luis; Rodríguez Perulero, Antonio

    2017-12-01

    The identification of specific aquifers that supply water to river systems is fundamental to understanding the dynamics of the rivers' hydrochemistry, particularly in arid and semiarid environments where river flow may be discontinuous. There are multiple methods to identify the source of river water. In this study of the River Andarax, in the Southeast of Spain, an analysis of natural tracers (physico-chemical parameters, uranium, radium and radon) in surface water and groundwater indicates that chemical parameters and uranium clearly identify the areas where there is groundwater-surface water interaction. The concentration of uranium found in the river defines two areas: the headwaters with U concentrations of 2 μg L -1 and the lower reaches, with U of 6 μg L -1 . Furthermore, variation in the 234 U/ 238 U isotopic ratio allowed us to detect the influence that groundwater from the carbonate aquifer has on surface water in the headwaters of the river, where the saline content is lower and the water has a calcium bicarbonate facies. The concentration of 226 Ra and 222 Rn are low in the surface waters: aquifer on the surface waters. The results of this study indicate the utility in the use of physico-chemical and radiological data conjointly as tracers of groundwater-surface water interaction in semiarid areas where the lithology of aquifers is diverse (carbonate and detritic) and where evaporitic rocks are present. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. Estimation of the recharge area contributing water to a pumped well in a glacial-drift, river-valley aquifer

    Science.gov (United States)

    Morrissey, Daniel J.

    1989-01-01

    The highly permeable, unconfined, glacial-drift aquifers that occupy most New England river valleys constitute the principal source of drinking water for many of the communities that obtain part or all of their public water supply from ground water. Recent events have shown that these aquifers are highly susceptible to contamination that results from a number of sources, such as seepage from wastewater lagoons, leaking petroleum-product storage tanks, and road salting. To protect the quality of water pumped from supply wells in these aquifers, it is necessary to ensure that potentially harmful contaminants do not enter the ground in the area that contributes water to the well. A high degree of protection can be achieved through the application of appropriate land-use controls within the contributing area. However, the contributing areas for most supply wells are not known. This report describes the factors that affect the size and shape of contributing areas to public supply wells and evaluates several methods that may be used to delineate contributing areas of wells in glacial-drift, river-valley aquifers. Analytical, two-dimensional numerical, and three-dimensional numerical models were used to delineate contributing areas. These methods of analysis were compared by applying them to a hypothetical aquifer having the dimensions and geometry of a typical glacial-drift, river-valley aquifer. In the model analyses, factors that control the size and shape of a contributing area were varied over ranges of values common to glacial-drift aquifers in New England. The controlling factors include the rate of well discharge, rate of recharge to the aquifer from precipitation and from adjacent till and bedrock uplands, distance of a pumping well from a stream or other potential source of induced recharge, degree of hydraulic connection of the aquifer with a stream, horizontal hydraulic conductivity of the aquifer, ratio of horizontal to vertical hydraulic conductivity, and

  7. Interactions between deep bedrock aquifers and surface water in function of recharge and topography: a numerical study

    Science.gov (United States)

    Goderniaux, P.; Davy, P.; Le Borgne, T.; Bresciani, E.; Jimenez-Martinez, J.

    2011-12-01

    In crystalline rock regions, such as Brittany (France), important reserves of groundwater into deep fractured aquifers are increasingly used and provide high quality water compared to shallow aquifers which can be subject to agricultural contamination. However, recharge processes of these deep aquifers and interactions with surface water are not yet fully understood. In some areas, intensive pumping is carried out without guarantee of the resource quantity and quality. Understanding these processes is crucial for sustainable management of the resource. In this study, we study how deep groundwater fluxes, pathways, ages, and river-aquifer interactions vary according to recharge. We assume that water flowing from the ground surface is distributed between shallow more permeable layers and deep layers. This repartition mostly depends on recharge rates. With high recharge, groundwater levels are high and subsurface streamlines are relatively short between recharge areas and existing draining rivers, which constitutes a very dense network. Therefore, most of the groundwater fluxes occur through the more permeable shallow layers. With low recharge, groundwater levels are lower, and river and shallow permeable levels are partly disconnected from each other. This induces a general increase of the groundwater streamlines length from the recharge areas to more sporadic discharge areas, and more fluxes occur through the deep layers. Recharge conditions and river-aquifer interactions have changed over the last thousands of years, due to change in precipitation, temperatures, existence of permafrost, etc. They have strongly influenced deep groundwater fluxes and can explain current groundwater age and flux distribution. To study these interactions, a regional-scale finite difference flow model was implemented. The model covers an area of 1400 km 2 , a depth of 1 km, and the topography is characteristic of Brittany. As rivers are mainly fed by groundwater drainage, seepages faces

  8. Interactions of diffuse and focused allogenic recharge in an eogenetic karst aquifer (Florida, USA)

    Science.gov (United States)

    Langston, Abigail L.; Screaton, Elizabeth J.; Martin, Jonathan B.; Bailly-Comte, Vincent

    2012-06-01

    The karstic upper Floridan aquifer in north-central Florida (USA) is recharged by both diffuse and allogenic recharge. To understand how recharged water moves within the aquifer, water levels and specific conductivities were monitored and slug tests were conducted in wells installed in the aquifer surrounding the Santa Fe River Sink and Rise. Results indicate that diffuse recharge does not mix rapidly within the aquifer but instead flows horizontally. Stratification may be aided by the high matrix porosity of the eogenetic karst aquifer. Purging wells for sample collection perturbed conductivity for several days, reflecting mixing of the stratified water and rendering collection of representative samples difficult. Interpretive numerical simulations suggest that diffuse recharge impacts the intrusion of allogenic water from the conduit by increasing hydraulic head in the surrounding aquifer and thereby reducing influx to the aquifer from the conduit. In turn, the increase of head within the conduits affects flow paths of diffuse recharge by moving newly recharged water vertically as the water table rises and falls. This movement may result in a broad vertical zone of dissolution at the water table above the conduit system, with thinner and more focused water-table dissolution at greater distance from the conduit.

  9. Advances in understanding river-groundwater interactions

    Science.gov (United States)

    Brunner, Philip; Therrien, René; Renard, Philippe; Simmons, Craig T.; Franssen, Harrie-Jan Hendricks

    2017-09-01

    River-groundwater interactions are at the core of a wide range of major contemporary challenges, including the provision of high-quality drinking water in sufficient quantities, the loss of biodiversity in river ecosystems, or the management of environmental flow regimes. This paper reviews state of the art approaches in characterizing and modeling river and groundwater interactions. Our review covers a wide range of approaches, including remote sensing to characterize the streambed, emerging methods to measure exchange fluxes between rivers and groundwater, and developments in several disciplines relevant to the river-groundwater interface. We discuss approaches for automated calibration, and real-time modeling, which improve the simulation and understanding of river-groundwater interactions. Although the integration of these various approaches and disciplines is advancing, major research gaps remain to be filled to allow more complete and quantitative integration across disciplines. New possibilities for generating realistic distributions of streambed properties, in combination with more data and novel data types, have great potential to improve our understanding and predictive capabilities for river-groundwater systems, especially in combination with the integrated simulation of the river and groundwater flow as well as calibration methods. Understanding the implications of different data types and resolution, the development of highly instrumented field sites, ongoing model development, and the ultimate integration of models and data are important future research areas. These developments are required to expand our current understanding to do justice to the complexity of natural systems.

  10. Potential effects of deepening the St. Johns River navigation channel on saltwater intrusion in the surficial aquifer system, Jacksonville, Florida

    Science.gov (United States)

    Bellino, Jason C.; Spechler, Rick M.

    2013-01-01

    The U.S. Army Corps of Engineers (USACE) has proposed dredging a 13-mile reach of the St. Johns River navigation channel in Jacksonville, Florida, deepening it to depths between 50 and 54 feet below North American Vertical Datum of 1988. The dredging operation will remove about 10 feet of sediments from the surficial aquifer system, including limestone in some locations. The limestone unit, which is in the lowermost part of the surficial aquifer system, supplies water to domestic wells in the Jacksonville area. Because of density-driven hydrodynamics of the St. Johns River, saline water from the Atlantic Ocean travels upstream as a saltwater “wedge” along the bottom of the channel, where the limestone is most likely to be exposed by the proposed dredging. A study was conducted to determine the potential effects of navigation channel deepening in the St. Johns River on salinity in the adjacent surficial aquifer system. Simulations were performed with each of four cross-sectional, variable-density groundwater-flow models, developed using SEAWAT, to simulate hypothetical changes in salinity in the surficial aquifer system as a result of dredging. The cross-sectional models were designed to incorporate a range of hydrogeologic conceptualizations to estimate the effect of uncertainty in hydrogeologic properties. The cross-sectional models developed in this study do not necessarily simulate actual projected conditions; instead, the models were used to examine the potential effects of deepening the navigation channel on saltwater intrusion in the surficial aquifer system under a range of plausible hypothetical conditions. Simulated results for modeled conditions indicate that dredging will have little to no effect on salinity variations in areas upstream of currently proposed dredging activities. Results also indicate little to no effect in any part of the surficial aquifer system along the cross section near River Mile 11 or in the water-table unit along the cross

  11. SRP baseline hydrogeologic investigation: Aquifer characterization. Groundwater geochemistry of the Savannah River Site and vicinity

    Energy Technology Data Exchange (ETDEWEB)

    Strom, R.N.; Kaback, D.S.

    1992-03-31

    An investigation of the mineralogy and chemistry of the principal hydrogeologic units and the geochemistry of the water in the principal aquifers at Savannah River Site (SRS) was undertaken as part of the Baseline Hydrogeologic Investigation. This investigation was conducted to provide background data for future site studies and reports and to provide a site-wide interpretation of the geology and geochemistry of the Coastal Plain Hydrostratigraphic province. Ground water samples were analyzed for major cations and anions, minor and trace elements, gross alpha and beta, tritium, stable isotopes of hydrogen, oxygen, and carbon, and carbon-14. Sediments from the well borings were analyzed for mineralogy and major and minor elements.

  12. Building Conceptual Models of Field-Scale Uranium Reactive Transport in a Dynamic Vadose Zone-Aquifer-River System

    International Nuclear Information System (INIS)

    Yabusaki, Steven B.; Fang, Yilin; Waichler, Scott R.

    2008-01-01

    Subsurface simulation is being used to build, test, and couple conceptual process models to better understand controls on a 0.4 km by 1.0 km uranium plume that has persisted above the drinking water standard in the groundwater of the Hanford 300 Area over the last 15 years. At this site, uranium-contaminated sediments in the vadose zone and aquifer are subject to significant variations in water levels and velocities driven by the diurnal, weekly, seasonal, and episodic Columbia River stage dynamics. Groundwater flow reversals typically occur twice a day with significant exchange of river water and groundwater in the near-river aquifer. Mixing of the dilute solution chemistry of the river with the groundwater complicates the uranium sorption behavior as the mobility of U(VI) has been shown experimentally to be a function of pH, carbonate, calcium, and uranium. Furthermore, uranium mass transfer between solid and aqueous phases has been observed to be rate-limited in the context of the high groundwater velocities resulting from the river stage fluctuations and the highly transmissive sediments (hydraulic conductivities ∼1500 m/d). One- and two-dimensional vertical cross-sectional simulations of variably-saturated flow and reactive transport, based on laboratory-derived models of distributed rate mass transfer and equilibrium multicomponent surface complexation, are used to assess uranium transport at the dynamic vadose zone aquifer interface as well as changes to uranium mobility due to incursions of river water into the aquifer

  13. Groundwater discharge to the Mississippi River and groundwater balances for the Interstate 94 Corridor surficial aquifer, Clearwater to Elk River, Minnesota, 2012–14

    Science.gov (United States)

    Smith, Erik A.; Lorenz, David L.; Kessler, Erich W.; Berg, Andrew M.; Sanocki, Chris A.

    2017-12-13

    The Interstate 94 Corridor has been identified as 1 of 16 Minnesota groundwater areas of concern because of its limited available groundwater resources. The U.S. Geological Survey, in cooperation with the Minnesota Department of Natural Resources, completed six seasonal and annual groundwater balances for parts of the Interstate 94 Corridor surficial aquifer to better understand its long-term (next several decades) sustainability. A high-precision Mississippi River groundwater discharge measurement of 5.23 cubic feet per second per mile was completed at low-flow conditions to better inform these groundwater balances. The recharge calculation methods RISE program and Soil-Water-Balance model were used to inform the groundwater balances. For the RISE-derived recharge estimates, the range was from 3.30 to 11.91 inches per year; for the SWB-derived recharge estimates, the range was from 5.23 to 17.06 inches per year.Calculated groundwater discharges ranged from 1.45 to 5.06 cubic feet per second per mile, a ratio of 27.7 to 96.4 percent of the measured groundwater discharge. Ratios of groundwater pumping to total recharge ranged from 8.6 to 97.2 percent, with the longer-term groundwater balances ranging from 12.9 to 19 percent. Overall, this study focused on the surficial aquifer system and its interactions with the Mississippi River. During the study period (October 1, 2012, through November 30, 2014), six synoptic measurements, along with continuous groundwater hydrographs, rainfall records, and a compilation of the pertinent irrigation data, establishes the framework for future groundwater modeling efforts.

  14. Lithology, hydrologic characteristics, and water quality of the Arkansas River Valley alluvial aquifer in the vicinity of Van Buren, Arkansas

    Science.gov (United States)

    Kresse, Timothy M.; Westerman, Drew A.; Hart, Rheannon M.

    2015-01-01

    A study to assess the potential of the Arkansas River Valley alluvial aquifer in the vicinity of Van Buren, Arkansas, as a viable source of public-supply water was conducted by the U.S. Geological Survey in cooperation with the Little Rock, District, U.S. Army Corps of Engineers. An important study component was to identify possible changes in hydrologic conditions following installation of James W. Trimble Lock and Dam 13 (December 1969) on the Arkansas River near the study area. Data were gathered for the study in regard to the lithology, hydrologic characteristics, and water quality of the aquifer. Lithologic information was obtained from drillers’ logs of wells drilled from 1957 through 1959. Water-quality samples were collected from 10 irrigation wells and analyzed for inorganic constituents and pesticides. To evaluate the potential viability of the alluvial aquifer in the Van Buren area, these data were compared to similar stratigraphic, lithologic, and groundwater-quality data from the Arkansas River Valley alluvial aquifer at Dardanelle, Ark., where the aquifer provides a proven, productive, sole-source of public-supply water.

  15. Stream-aquifer relations and the potentiometric surface of the Upper Floridan aquifer in the lower Apalachicola-Chattahoochee-Flint River basin in parts of Georgia, Florida, and Alabama, 1999-2000

    Science.gov (United States)

    Mosner, Melinda S.

    2002-01-01

    The Upper Floridan aquifer is the principal source of water for domestic and agricultural use in the lower Apalachicola-Chattahoochee-Flint (ACF) River Basin. Recent drought and increased water use have made understanding surface- and ground-water relations a priority for water-resource managers in the region. From July 1999 through August 2000, less than normal precipitation reduced streamflow in the area to less than 12 percent of average mean-daily streamflow and ground-water levels reached record or near-record lows. Effects of drought on stream-aquifer interactions in the basin were evaluated using baseflow estimation, ground-water seepage calculations, and potentiometric-surface maps. Ground-water discharge to streams, or baseflow, was estimated using three methods: field measurements, hydrograph separation, and linear regression analysis. Results were evaluated seasonally -- October 1999, April 2000, and August 2000 -- and for the period of record at four surface-water stations located on Kinchafoonee, Spring, Muckalee, and Turkey Creeks. Estimates of baseflow also were compared annually; ground-water discharge during the drought years, 1999 - 2000, was compared with ground-water discharge during a relatively wet year, 1994. Hydrograph separation indicated decreased base-flow of streams as the water level in the Upper Floridan aquifer declined. Mean-annual baseflow for Kinchafoonee, Spring, Muckalee, and Turkey Creeks ranged from 36 to 71 percent of total streamflow during the period of record. In 1994 baseflow accounted for only 37 to 56 percent of total streamflow, in 1999 baseflow comprised from 60 to 73 percent of total streamflow, and in 2000 baseflow comprised from 56 to 76 percent of streamflow. The percentage of total streamflow attributed to ground water increased during the drought, whereas other components of streamflow decreased (overland flow, interflow, and channel precipitation). Even though relative ground-water contributions were increased

  16. Hydrogeology of the Susquehanna River valley-fill aquifer system in the Endicott-Vestal area of southwestern Broome County, New York

    Science.gov (United States)

    Randall, Allan D.; Kappel, William M.

    2015-07-29

    The village of Endicott, New York, and the adjacent town of Vestal have historically used groundwater from the Susquehanna River valley-fill aquifer system for municipal water supply, but parts of some aquifers in this urban area suffer from legacy contamination from varied sources. Endicott would like to identify sites distant from known contamination where productive aquifers could supply municipal wells with water that would not require intensive treatment. The distribution or geometry of aquifers within the Susquehanna River valley fill in western Endicott and northwestern Vestal are delineated in this report largely on the basis of abundant borehole data that have been compiled in a table of well records.

  17. The impact of river water intrusion on trace metal cycling in karst aquifers: an example from the Floridan aquifer system at Madison Blue Spring, Florida

    Science.gov (United States)

    Brown, A. L.; Martin, J. B.; Screaton, E.; Spellman, P.; Gulley, J.

    2011-12-01

    Springs located adjacent to rivers can serve as recharge points for aquifers when allogenic runoff increases river stage above the hydraulic head of the spring, forcing river water into the spring vent. Depending on relative compositions of the recharged water and groundwater, the recharged river water could be a source of dissolved trace metals to the aquifer, could mobilize solid phases such as metal oxide coatings, or both. Whether metals are mobilized or precipitated should depend on changes in redox and pH conditions as dissolved oxygen and organic carbon react following intrusion of the river water. To assess how river intrusion events affect metal cycling in springs, we monitored a small recharge event in April 2011 into Madison Blue Spring, which discharges to the Withlacoochee River in north-central Florida. Madison Blue Spring is the entrance to a phreatic cave system that includes over 7.8 km of surveyed conduits. During the event, river stage increased over base flow conditions for approximately 25 days by a maximum of 8%. Intrusion of the river water was monitored with conductivity, temperature and depth sensors that were installed within the cave system and adjacent wells. Decreased specific conductivity within the cave system occurred for approximately 20 days, reflecting the length of time that river water was present in the cave system. During this time, grab samples were collected seven times over a period of 34 days for measurements of major ion and trace metal concentrations at the spring vent and at Martz sink, a karst window connected to the conduit system approximately 150 meters from the spring vent. Relative fractions of surface water and groundwater were estimated based on Cl concentrations of the samples, assuming conservative two end-member mixing during the event. This mixing model indicates that maximum river water contribution to the groundwater system was approximately 20%. River water had concentrations of iron, manganese, and other

  18. Sources of nitrate in water from springs and the Upper Floridan aquifer, Suwannee River basin, Florida

    Science.gov (United States)

    Katz, B.G.; Hornsby, H.D.; Böhlke, John Karl

    1999-01-01

    In the Suwannee River basin of northern Florida, nitrate-N concentrations are 1.5 to 20 mg 1-1 in waters of the karstic Upper Floridan aquifer and in springs that discharge into the middle reach of the Suwannee River. During 1996-1997, fertilizers and animal wastes from farming operations in Suwannee County contributed approximately 49% and 45% of the total N input, respectively. Values of ??15N-NO3 in spring waters range from 3.9??? to 5.8???, indicating that nitrate most likely originates from a mixture of inorganic (fertilizers) and organic (animal waste) sources. In Lafayette County, animal wastes from farming operations and fertilizers contributed approximately 53% and 39% of the total N input, respectively, but groundwater near dairy and poultry farms has ??15N-NO3 values of 11.0-12.1???, indicative of an organic source of nitrate. Spring waters that discharge to the Suwannee River from Lafayette County have ??15N-NO3 values of 5.4-8.39???, which are indicative of both organic and inorganic sources. Based on analyses of CFCs, the mean residence time of shallow groundwater and spring water ranges between 8-12 years and 12-25 years, respectively.

  19. Beryllium in river baseflow, shallow groundwaters and major aquifers of the U.K

    International Nuclear Information System (INIS)

    Edmunds, W.M.; Trafford, J.M.

    1993-01-01

    Out of 924 samples from 13 aquifer units in the United Kingdom, Be was detected in only 12. In carbonate aquifers no Be was found above the detection limit of 0.05 μg/1. The occurrence of Be was restricted to arenaceous aquifers where concentrations up to 1 μg/1 were found mainly in the Carboniferous Millstone Grit and Lower Cretaceous Lower Greensand. Interstitial water profiles from the unsaturated zones of the Lower Greensand and Triassic sandstone contain Be concentrations in excess of 10 μg/1 within the top 10 m which may persist to the water table at concentrations near to 1 μg/1. The only major anomaly to be found in river baseflow was from the Mourne Mountains of Northern Ireland where Be concentrations of up to 4.7 μg/1 were found associated with the outcrop of the Tertiary granite intrusion. Elsewhere, Be (0.22 μg/1) was found in neutral groundwaters derived from granite feeding the acid Loch Fleet (southern Scotland) in which concentrations of 0.09 μg/1 were maintained. Beryllium occurrence therefore depends strongly on geology. The predominant aqueous species below pH 5.5 is Be 2+ and above this Be(OH) + dominates. The presence of high Al in most waters sampled greatly suppresses the formation of BeF complex ions. Beryllium shows close geochemical behaviour with Mg across a range of pH which may have environmental consequences, if Be substitution for Mg takes place. (author)

  20. Field Investigation of Stream-Aquifer Interactions: A Case Study in Coastal California

    Science.gov (United States)

    Pritchard-Peterson, D.; Malama, B.

    2017-12-01

    We report here results of a detailed investigation of the dynamic interaction between a stream and an alluvial aquifer at Swanton Pacific Ranch in the Scotts Creek watershed, Santa Cruz County, California. The aquifer is an important source of groundwater for cropland irrigation and for aquatic ecosystem support. Low summer base flows in Scotts Creek are a source of serious concern for land managers, fisheries biologists, and regulatory agencies due to the presence of federally protected steelhead trout and coho salmon. An understanding of the interaction between the stream and pumped aquifer will allow for assessment of the impacts of groundwater extraction on stream flows and is essential to establishing minimum flow requirements. This will aid in the development of sustainable riparian groundwater pumping practices that meet agricultural and ecological needs. Results of extensive direct-push sampling of the subsurface, laboratory falling-head permeameter tests and particle size analysis of aquifer sediments, multi-day pumping tests, long-term passive monitoring of aquifer hydraulic heads and stream stage and discharge, and electrical resistivity interrogation of the subsurface are reported here. Findings indicate that the permeable subsurface formation tapped by irrigation wells is a leaky semi-confined aquifer, overlain by a thin low permeability layer of silt and clay above which lies Scotts Creek. These results are particularly useful to land managers responsible for groundwater abstraction from wells that tap into the aquifer. Additionally, an index of stream-aquifer connectivity is proposed that would allow land managers to conveniently modify groundwater abstraction practices, minimizing concerns of stream depletion.

  1. A conceptual model for groundwater - surface water interactions in the Darling River Floodplain, N.S.W., Australia

    Science.gov (United States)

    Brodie, R. S.; Lawrie, K.; Somerville, P.; Hostetler, S.; Magee, J.; Tan, K. P.; Clarke, J.

    2013-12-01

    Multiple lines of evidence were used to develop a conceptual model for interaction between the Darling River and associated floodplain aquifers in western New South Wales, Australia. Hydrostratigraphy and groundwater salinities were mapped using airborne electromagnetics (AEM), validated by sonic-core drilling. The AEM was highly effective in mapping groundwater freshening due to river leakage in discrete zones along the river corridor. These fresh resources occurred in both the unconfined Quaternary aquifers and the underlying, largely semi-confined Pliocene aquifers. The AEM was also fundamental to mapping the Blanchetown Clay aquitard which separates these two aquifer systems. Major-ion chemistry highlighted a mixing signature between river waters and groundwaters in both the Quaternary and Pliocene aquifers. Stable isotope data indicates that recharge to the key Pliocene aquifers is episodic and linked to high-flow flood events rather than river leakage being continuous. This was also evident when groundwater chemistry was compared with river chemistry under different flow conditions. Mapping of borehole levels showed groundwater mounding near the river, emphasising the regional significance of losing river conditions for both aquifer systems. Critically, rapid and significant groundwater level responses were measured during large flood events. In the Pliocene aquifers, continuation of rising trends after the flood peak receded confirms that this is an actual recharge response rather than hydraulic loading. The flow dependency of river leakage can be explained by the presence of mud veneers and mineral precipitates along the Darling River channel bank when river flows are low. During low flow conditions these act as impediments to river leakage. During floods, high flow velocities scour these deposits, revealing lateral-accretion surfaces in the shallow scroll plain sediments. This scouring allows lateral bank recharge to the shallow aquifer. During flood

  2. Severe petrol contamination in the aquifer of the Llobregat river delta

    International Nuclear Information System (INIS)

    Garcia Gonzalez, E.

    1993-01-01

    On 16-09-91 an attack on an oil pipeline led to some 70 tons of petrol spilling out and catching fire. About 20 tons filtered down into the aquifer of the river Llobregat delta. On 08-12-91 the presence of petrol was detected in a well used for supplying water about 1 km downstream. A system was set up for monitoring and extracting the polluted ground water. The volume affected had now reached 3.5 hm''3. The decontamination costs came to 245 million pesetas in comparison to only 10 millions pesetas for the petrol spill. The cost of extracting the water was 70 pta/m''3. Finally the importance of regional planning and the need to prevent such accidents is pointed out. The means necessary to deal with them should be available. (Author)

  3. The quality of our Nation's waters: water quality in the Mississippi embayment-Texas coastal uplands aquifer system and Mississippi River Valley alluvial aquifer, south-central United States, 1994-2008

    Science.gov (United States)

    Kingsbury, James A.; Barlow, Jeannie R.; Katz, Brian G.; Welch, Heather L.; Tollett, Roland W.; Fahlquist, Lynne S.

    2015-01-01

    About 8 million people rely on groundwater from the Mississippi embayment—Texas coastal uplands aquifer system for drinking water. The Mississippi River Valley alluvial aquifer also provides drinking water for domestic use in rural areas but is of primary importance to the region as a source of water for irrigation. Irrigation withdrawals from this aquifer are among the largest in the Nation and play a key role in the economy of the area, where annual crop sales total more than $7 billion. The reliance of the region on both aquifers for drinking water and irrigation highlights the importance of long-term management to sustain the availability and quality of these resources.

  4. Geohydrology of the valley-fill aquifer in the Ramapo and Mahwah rivers area, Rockland County, New York

    Science.gov (United States)

    Moore, Richard Bridge; Cadwell, D.H.; Stelz, W.G.; Belli, J.L.

    1982-01-01

    This report is the eighth in a series of 11 map sets depicting geohydrologic conditions in selected aquifers in upstate New York. Geohydrologic data are compiled on six maps at 1:24,000 scale. Together, the maps provide a comprehensive overview of a major valley-fill aquifer in southeastern Rockland County. The maps include surficial geology, geologic sections, water-infiltration potential of soil zone, aquifer thickness, water-table elevations, well yields, and land use. The valley-fill deposits consists of alluvial silt and sand, glacial outwash (sand and gravel), ice-contact sand and gravel, till, and lacustrine silt and clay. The sand and gravel beds have relatively high permeabilities, whereas the till, silt, and clay deposits have relatively low permeabilities. Water-table conditions prevail in unconfined sand and gravel along the Ramapo River valley and much of the Mahwah River valley. Artesian conditions prevail in confined sand and gravel buried under silt and clay and till in parts of the Mahway valley. The aquifer is recharged throughout, where the land surface is most permeable and is greatest along the margin of the valley, where runoff from the hillsides is concentrated. The use of land overlying the aquifer is predominantly commercial, agricultural and residential, with lesser industrial uses. (USGS)

  5. Potentiometric surface of the Upper Floridan aquifer in the St. Johns River water management district and vicinity, Florida, September 2005

    Science.gov (United States)

    Kinnaman, Sandra L.

    2006-01-01

    This map depicts the potentiometric surface of the Upper Floridan aquifer in the St. Johns River Water Management District and vicinity for September 2005. Potentiometric contours are based on water-level measurements collected at 643 wells during the period September 12-28, near the end of the wet season. Some contours are inferred from previous potentiometric-surface maps with larger well networks. The potentiometric surface of the carbonate Upper Floridan aquifer responds mainly to rainfall, and more locally, to ground-water withdrawals and springflow. Potentiometric-surface highs generally correspond to topographic highs where the aquifer is recharged. Springs and areas of diffuse upward leakage naturally discharge water from the aquifer and are most prevalent along the St. Johns River. Areas of discharge are reflected by depressions in the potentiometric surface. Ground-water withdrawals locally have lowered the potentiometric surface. Ground water in the Upper Floridan aquifer generally flows from potentiometric highs to potentiometric lows in a direction perpendicular to the contours.

  6. Potentiometric Surface of the Upper Floridan Aquifer in the St. Johns River Water Management District and Vicinity, Florida, September 2008

    Science.gov (United States)

    Kinnaman, Sandra L.; Dixon, Joann F.

    2009-01-01

    This map depicts the potentiometric surface of the Upper Floridan aquifer in the St. Johns River Water Management District and vicinity for September 2008. Potentiometric contours are based on water-level measurements collected at 589 wells during the period September 15-25, near the end of the wet season. Some contours are inferred from previous potentiometric-surface maps with larger well networks. The potentiometric surface of the carbonate Upper Floridan aquifer responds mainly to rainfall, and more locally, to ground-water withdrawals and spring flow. Potentiometric-surface highs generally correspond to topographic highs where the aquifer is recharged. Springs and areas of diffuse upward leakage naturally discharge water from the aquifer and are most prevalent along the St. Johns River. Areas of discharge are reflected by depressions in the potentiometric surface. Ground-water withdrawals locally have lowered the potentiometric surface. Ground water in the Upper Floridan aquifer generally flows from potentiometric highs to potentiometric lows in a direction perpendicular to the contours.

  7. Potentiometric Surface of the Upper Floridan Aquifer in the St. Johns River Water Management District and Vicinity, Florida, September 2007

    Science.gov (United States)

    Kinnaman, Sandra L.; Dixon, Joann F.

    2008-01-01

    This map depicts the potentiometric surface of the Upper Floridan aquifer in the St. Johns River Water Management District and vicinity for September 2007. Potentiometric contours are based on water-level measurements collected at 554 wells during the period September 15-27, near the end of the wet season. Some contours are inferred from previous potentiometric-surface maps with larger well networks. The potentiometric surface of the carbonate Upper Floridan aquifer responds mainly to rainfall, and more locally, to ground-water withdrawals and spring flow. Potentiometric-surface highs generally correspond to topographic highs where the aquifer is recharged. Springs and areas of diffuse upward leakage naturally discharge water from the aquifer and are most prevalent along the St. Johns River. Areas of discharge are reflected by depressions in the potentiometric surface. Ground-water withdrawals locally have lowered the potentiometric surface. Ground water in the Upper Floridan aquifer generally flows from potentiometric highs to potentiometric lows in a direction perpendicular to the contours.

  8. Potentiometric surface of the upper Floridan Aquifer in the St. Johns River Water Management District and vicinity, Florida, September, 2004

    Science.gov (United States)

    Kinnaman, Sandra L.

    2005-01-01

    Introduction: This map depicts the potentiometric surface of the Upper Floridan aquifer in the St. Johns River Water Management District and vicinity in September 2004. Potentiometric contours are based on water-level measurements collected at 608 wells during the period September 14-October 1, near the end of the wet season. The shapes of some contours have been inferred from previous potentiometric-surface maps with larger well networks. The potentiometric surface of the carbonate Upper Floridan aquifer responds mainly to rainfall, and more locally, to ground-water withdrawals. Potentiometric-surface highs generally correspond to topographic highs where the aquifer is recharged. Springs and areas of diffuse upward leakage naturally discharge water from the aquifer and are most prevalent along the St. Johns River. Areas of discharge are reflected by depressions in the potentiometric surface. Ground-water withdrawals locally have lowered the potentiometric surface. Ground water in the Upper Floridan aquifer generally flows from potentiometric highs to potentiometric lows in a direction perpendicular to the contours.

  9. Potentiometric Surface of the Upper Floridan Aquifer in the St. Johns River Water Management District and Vicinity, Florida, May, 2004

    Science.gov (United States)

    Kinnaman, Sandra L.; Knowles, Leel

    2004-01-01

    INTRODUCTION This map depicts the potentiometric surface of the Upper Floridan aquifer in the St. Johns River Water Management District and vicinity in May 2001. Potentiometric contours are based on water-level measurements collected at 684 wells during the period May 2 - 30, near the end of the dry season. The shapes of some contours have been inferred from previous potentiometric-surface maps with larger well networks. The potentiometric surface of the carbonate Upper Floridan aquifer responds mainly to rainfall, and more locally, to ground-water withdrawals. Potentiometric-surface highs generally correspond to topographic highs where the aquifer is recharged. Springs and areas of diffuse upward leakage naturally discharge water from the aquifer and are most prevalent along the St. Johns River. Areas of discharge are reflected by depressions in the potentiometric surface. Ground-water withdrawals locally have lowered the potentiometric surface. Ground water in the Upper Floridan aquifer generally flows from potentiometric highs to potentiometric lows in a direction perpendicular to the contours.

  10. Potentiometric Surface of the Upper Floridan Aquifer in the St. Johns River Water Management District and Vicinity, Florida, September 2006

    Science.gov (United States)

    Kinnaman, Sandra L.; Dixon, Joann F.

    2007-01-01

    Introduction This map depicts the potentiometric surface of the Upper Floridan aquifer in the St. Johns River Water Management District and vicinity for September 2006. Potentiometric contours are based on water-level measurements collected at 571 wells during the period September 11-29, near the end of the wet season. Some contours are inferred from previouspotentiometric-surface maps with larger well networks. The potentiometric surface of the carbonate Upper Floridan aquifer responds mainly to rainfall, and more locally, to ground-water withdrawals and spring flow. Potentiometric-surface highs generally correspond to topographic highs where the aquifer is recharged. Springs and areas of diffuse upward leakage naturally discharge water from the aquifer and are most prevalent along the St. Johns River. Areas of discharge are reflected by depressions in the potentiometric surface. Ground-water withdrawals locally have lowered the potentiometric surface. Ground water in the Upper Floridan aquifer generally flows from potentiometric highs to potentiometric lows in a direction perpendicular to the contours.

  11. Potentiometric Surface of the Upper Floridan Aquifer in the St. Johns River Water Management District and Vicinity, Florida, May 2006

    Science.gov (United States)

    Kinnaman, Sandra L.

    2006-01-01

    Introduction: This map depicts the potentiometric surface of the Upper Floridan aquifer in the St. Johns River Water Management District and vicinity for May 2006. Potentiometric contours are based on water-level measurements collected at 599 wells during the period May 14-31, near the end of the dry season. Some contours are inferred from previous potentiometric-surface maps with larger well networks. The potentiometric surface of the carbonate Upper Floridan aquifer responds mainly to rainfall, and more locally, to ground-water withdrawals and springflow. Potentiometric-surface highs generally correspond to topographic highs where the aquifer is recharged. Springs and areas of diffuse upward leakage naturally discharge water from the aquifer and are most prevalent along the St. Johns River. Areas of discharge are reflected by depressions in the potentiometric surface. Ground-water withdrawals locally have lowered the potentiometric surface. Ground water in the Upper Floridan aquifer generally flows from potentiometric highs to potentiometric lows in a direction perpendicular to the contours.

  12. Potentiometric Surface of the Upper Floridan Aquifer in the St. Johns River Water Management District and Vicinity, Florida, May 2007

    Science.gov (United States)

    Kinnaman, Sandra L.; Dixon, Joann F.

    2007-01-01

    Introduction This map depicts the potentiometric surface of the Upper Floridan aquifer in the St. Johns River Water Management District and vicinity for May 2007. Potentiometric contours are based on water-level measurements collected at 566 wells during the period May 4-June 11 near the end of the dry season, however most of the water level data for this map were collected by the U.S. Geological Survey during the period May 21-25, 2007. Some contours are inferred from previous potentiometric-surface maps with larger well networks. The potentiometric surface of the carbonate Upper Floridan aquifer responds mainly to rainfall, and more locally, to ground-water withdrawals and spring flow. Potentiometric-surface highs generally correspond to topographic highs where the aquifer is recharged. Springs and areas of diffuse upward leakage naturally discharge water from the aquifer and are most prevalent along the St. Johns River. Areas of discharge are reflected by depressions in the potentiometric surface. Ground-water withdrawals locally have lowered the potentiometric surface. Ground water in the Upper Floridan aquifer generally flows from potentiometric highs to potentiometric lows in a direction perpendicular to the contours.

  13. Flow of river water into a karstic limestone aquifer-2. Dating the young fraction in groundwater mixtures in the Upper Floridan aquifer near Valdosta, Georgia

    Energy Technology Data Exchange (ETDEWEB)

    Plummer, L.N.; Busenberg, E. [U.S. Geological Survey, 432 National Center, Reston, VA (United States); Drenkard, S.; Schlosser, P.; Ekwurzel, B.; Weppernig, R. [Lamont-Doherty Earth Observatory of Columbia University, 61 Route 9W, Palisades, NY (United States); McConnell, J.B. [U.S. Geological Survey, 3039 Amwiler Rd., Atlanta, GA (United States); Michel, R.L. [U.S. Geological Survey, Mail Stop 434, 345 Middlefield Road, Menlo Park, CA (United States)

    1998-11-01

    Tritium/helium-3 ({sup 3}H/{sup 3}He) and chlorofluorocarbon (CFCs, CFC-11, CFC-12, CFC-113) data are used to date the young fraction in groundwater mixtures from a karstic limestone aquifer near Valdosta, Georgia, where regional paleowater in the Upper Floridan aquifer receives recharge from two young sources-the flow of Withlacoochee River water through sinkholes in the river bed, and leakage of infiltration water through post-Eocene semi-confining beds above the Upper Floridan aquifer. In dating the young fraction of mixtures using CFCs, it is necessary to reconstruct the CFC concentration that was in the young fraction prior to mixing. The {sup 3}H/{sup 3}He age is independent of the extent of dilution with older ({sup 3}H-free and {sup 3}He{sub trit}-free) water. The groundwater mixtures are designated as Type-1 for mixtures of regional paleowater and regional infiltration water and Type-2 for mixtures containing more than approximately 4% of river water. The fractions of regional paleowater, regional infiltration water, and Withlacoochee River water in the groundwater mixtures were determined from Cl{sup -} and {delta}{sup 18}O data for water from the Upper Floridan aquifer at Valdosta, Georgia.The chlorofluorocarbons CFC-11 and CFC-113 are removed by microbial degradation and/or sorption processes in most anaerobic (Type-2) groundwater at Valdosta, but are present in some aerobic Type-1 water. CFC-12 persists in both SO{sub 4}-reducing and methanogenic water. The very low detection limits for CFCs (approximately 0.3 pg kg{sup -1}) permitted CFC-11 and CFC-12 dating of the fraction of regional infiltration water in Type-1 mixtures, and CFC-12 dating of the river-water fraction in Type-2 mixtures. Overall, approximately 50% of the 85 water samples obtained from the Upper Floridan aquifer have CFC-12-based ages of the young fraction that are consistent with the {sup 3}H concentration of the groundwater. Because of uncertainties associated with very low {sup 3}H

  14. Chlorine-36 in the Snake River Plain aquifer at the Idaho National Engineering Laboratory: Origin and implications

    International Nuclear Information System (INIS)

    Beasley, T.M.; Cecil, L.D.; Mann, L.J.; Sharma, P.; Fehn, U.; Gove, H.E.; Kubik, P.W.

    1993-01-01

    Between 1952 and 1984, low-level radioactive waste was introduced directly into the Snake River Plain aquifer at the Idaho National Engineering Laboratory (INEL), Idaho Falls, Idaho. These wastes were generated, principally, at the nuclear fuel reprocessing facility on the site. The measurements of 36 Cl in monitoring and production well waters, downgradient from disposal wells and seepage ponds, found easily detectable, nonhazardous concentrations of this radionuclide from the point of injection to the INEL southern site boundary. Comparisons are made between 3 H and 36 Cl concentrations in aquifer water and the advantages of 36 Cl as a tracer of subsurface-water dynamics at the site are discussed

  15. Chlorine-36 in the Snake River Plain Aquifer at the Idaho National Engineering Laboratory; origin and implications

    Science.gov (United States)

    Beasley, T.M.; Cecil, L.D.; Sharma, P.; Kubik, P.W.; Fehn, U.; Mann, L.J.; Gove, H.E.

    1993-01-01

    Between 1952 and 1984, low-level radioactive waste was introduced directly into the Snake River Plain aquifer at the Idaho National Engineering Laboratory (INEL), Idaho Falls, Idaho. These wastes were generated, principally, at the nuclear fuel reprocessing facility on the site. Our measurements of 36C1 in monitoring and production well waters, downgradient from disposal wells and seepage ponds, found easily detectable, nonhazardous concentrations of this radionuclide from the point of injection to the INEL southern site boundary. Comparisons are made between 3H and 36Cl concentrations in aquifer water and the advantages of 36C1 as a tracer of subsurface-water dynamics at the site are discussed.

  16. Assessing the impact of managed aquifer recharge on seasonal low flows in a semi-arid alluvial river

    Science.gov (United States)

    Ronayne, M. J.; Roudebush, J. A.; Stednick, J. D.

    2016-12-01

    Managed aquifer recharge (MAR) is one strategy that can be used to augment seasonal low flows in alluvial rivers. Successful implementation requires an understanding of spatio-temporal groundwater-surface water exchange. In this study we conducted numerical groundwater modeling to analyze the performance of an existing MAR system in the South Platte River Valley in northeastern Colorado (USA). The engineered system involves a spatial reallocation of water during the winter months; alluvial groundwater is extracted near the river and pumped to upgradient recharge ponds, with the intent of producing a delayed hydraulic response that increases the riparian zone water table (and therefore streamflow) during summer months. Higher flows during the summer are required to improve riverine habitat for threatened species in the Platte River. Modeling scenarios were constrained by surface (streamflow gaging) and subsurface (well data) measurements throughout the study area. We compare two scenarios to analyze the impact of MAR: a natural base case scenario and an active management scenario that includes groundwater pumping and managed recharge. Steady-periodic solutions are used to evaluate the long-term stabilized behavior of the stream-aquifer system with and without pumping/recharge. Streamflow routing is included in the model, which permits quantification of the timing and location of streamflow accretion (increased streamflow associated with MAR). An analysis framework utilizing capture concepts is developed to interpret seasonal changes in head-dependent flows to/from the aquifer, including groundwater-surface water exchange that impacts streamflow. Results demonstrate that accretion occurs during the target low-flow period but is not limited to those months, highlighting an inefficiency that is a function of the aquifer geometry and hydraulic properties. The results of this study offer guidance for other flow augmentation projects that rely on water storage in shallow

  17. Use of computer programs STLK1 and STWT1 for analysis of stream-aquifer hydraulic interaction

    Science.gov (United States)

    Desimone, Leslie A.; Barlow, Paul M.

    1999-01-01

    Quantifying the hydraulic interaction of aquifers and streams is important in the analysis of stream base fow, flood-wave effects, and contaminant transport between surface- and ground-water systems. This report describes the use of two computer programs, STLK1 and STWT1, to analyze the hydraulic interaction of streams with confined, leaky, and water-table aquifers during periods of stream-stage fuctuations and uniform, areal recharge. The computer programs are based on analytical solutions to the ground-water-flow equation in stream-aquifer settings and calculate ground-water levels, seepage rates across the stream-aquifer boundary, and bank storage that result from arbitrarily varying stream stage or recharge. Analysis of idealized, hypothetical stream-aquifer systems is used to show how aquifer type, aquifer boundaries, and aquifer and streambank hydraulic properties affect aquifer response to stresses. Published data from alluvial and stratifed-drift aquifers in Kentucky, Massachusetts, and Iowa are used to demonstrate application of the programs to field settings. Analytical models of these three stream-aquifer systems are developed on the basis of available hydrogeologic information. Stream-stage fluctuations and recharge are applied to the systems as hydraulic stresses. The models are calibrated by matching ground-water levels calculated with computer program STLK1 or STWT1 to measured ground-water levels. The analytical models are used to estimate hydraulic properties of the aquifer, aquitard, and streambank; to evaluate hydrologic conditions in the aquifer; and to estimate seepage rates and bank-storage volumes resulting from flood waves and recharge. Analysis of field examples demonstrates the accuracy and limitations of the analytical solutions and programs when applied to actual ground-water systems and the potential uses of the analytical methods as alternatives to numerical modeling for quantifying stream-aquifer interactions.

  18. Surface complexation modeling of groundwater arsenic mobility: Results of a forced gradient experiment in a Red River flood plain aquifer, Vietnam

    DEFF Research Database (Denmark)

    Jessen, Søren; Postma, Dieke; Larsen, Flemming

    2012-01-01

    , suggesting a comparable As(III) affinity of Holocene and Pleistocene aquifer sediments. A forced gradient field experiment was conducted in a bank aquifer adjacent to a tributary channel to the Red River, and the passage in the aquifer of mixed groundwater containing up to 74% channel water was observed......Three surface complexation models (SCMs) developed for, respectively, ferrihydrite, goethite and sorption data for a Pleistocene oxidized aquifer sediment from Bangladesh were used to explore the effect of multicomponent adsorption processes on As mobility in a reduced Holocene floodplain aquifer......(III) while PO43− and Fe(II) form the predominant surface species. The SCM for Pleistocene aquifer sediment resembles most the goethite SCM but shows more Si sorption. Compiled As(III) adsorption data for Holocene sediment was also well described by the SCM determined for Pleistocene aquifer sediment...

  19. Lava tubes and aquifer vulnerability in the upper Actopan River basin, Veracruz, México

    Science.gov (United States)

    Espinasa-Pereña, R.; Delgado Granados, H.

    2011-12-01

    Rapid infiltration leads to very dry conditions on the surface of some volcanic terrains, with large allogenic streams sometimes sinking underground upon reaching a lava flow. Aquifers in lava flows tend to be heterogeneous and discontinuous, generally unconfined and fissured, and have high transmissivity. Springs associated with basalts may be very large but are typically restricted to lava-flow margins. Concern has been expressed regarding the potential for lava-tube caves to facilitate groundwater contamination similar to that afflicting some karst aquifers (Kempe et al., 2003; Kiernan et al., 2002; Halliday 2003). The upper Actopan River basin is a series of narrow valleys excavated in Tertiary volcanic brechias. Several extensive Holocene basaltic tube-fed lava flows have partially filled these valleys. The youngest and longest flow originates at El Volcancillo, a 780 ybP monogenetic volcano. It is over 50 km long, and was fed through a major master tube, the remains of which form several lava-tube caves (Gassos and Espinasa-Pereña, 2008). Another tube-fed flow initiates at a vent at the bottom of Barranca Huichila and can be followed for 7 km to where it is covered by the Volcancillo flow. The Huichila River is captured by this system of lava tubes and can be followed through several underground sections. In dry weather the stream disappears at a sump in one of these caves, although during hurricanes it overflows the tube, floods the Tengonapa plain, and finally sinks through a series of skylights into the master tube of the Volcancillo flow. Near villages, the cave entrances are used as trash dumps, which are mobilized during floods. These include household garbage, organic materials associated with agriculture and even medical supplies. This is a relatively recent phenomenon, caused by population growth and the building of houses above the lava flows. The water resurges at El Descabezadero, gushing from fractures in the lava above the underlying brechias

  20. Assessing the contribution of the main aquifer of Loire basin to the river discharge during low flow

    International Nuclear Information System (INIS)

    Monteil, C.

    2011-01-01

    The evolution of the Loire river low flows is a key issue for various uses such as water supply, irrigation or industrial needs. Power production is a major activity in the Loire basin with four nuclear power plants using the river water for the cooling system. To estimate the evolution of long term in-stream low flow distribution, it is necessary to have a good estimate of the contribution of a complex aquifer system to the river discharge. Three main overlaying aquifer units covering an area of 38000 km 2 are considered: Beauce Limestones (Oligocene), Chalks (Seno-Turonian) and Sands (Cenomanian). A distributed hydrogeological model (Eau-Dyssee) is implemented with the coupling of five modules: surface water budget, watershed routing, river routing, unsaturated zone transfer, and groundwater flow. The model is calibrated over a 10-yr period, validated over another 10-yr period, and then a test simulation is run over 35 years. A hybrid fitting methodology, based on an automated inverse method and a trial-error one, has been developed for the fitting of the Beauce aquifer unit. The other units are calibrated by trial and error. The fitted model simulates properly both discharges and piezometric heads over the whole domain, with a global RMSE between simulated and observed piezometric heads of 2.86 m, and all Nash efficiency at the Loire discharge gauging stations over 0.9. The fitted model has then been used to quantify the hydro-system mass balance at different time scales. Mean aquifer contribution to Loire river discharge during low flow between 1975 and 2008 is estimated at 15 m 3 /s. First results of simulations under four different climate change projections indicate an averaged decrease of these contributions reaching 8 to 50% in 2100. (author)

  1. Using artificial sweeteners to identify contamination sources and infiltration zones in a coupled river-aquifer system

    Science.gov (United States)

    Bichler, Andrea; Muellegger, Christian; Hofmann, Thilo

    2014-05-01

    In shallow or unconfined aquifers the infiltration of contaminated river water might be a major threat to groundwater quality. Thus, the identification of possible contamination sources in coupled surface- and groundwater systems is of paramount importance to ensure water quality. Micropollutants like artificial sweeteners are promising markers for domestic waste water in natural water bodies. Compounds, such as artificial sweeteners, might enter the aquatic environment via discharge of waste water treatment plants, leaky sewer systems or septic tanks and are ubiquitously found in waste water receiving waters. The hereby presented field study aims at the (1) identification of contamination sources and (2) delineation of infiltration zones in a connected river-aquifer system. River bank filtrate in the groundwater body was assessed qualitatively and quantitatively using a combined approach of hydrochemical analysis and artificial sweeteners (acesulfame ACE) as waste water markers. The investigated aquifer lies within a mesoscale alpine head water catchment and is used for drinking water production. It is hypothesized that a large proportion of the groundwater flux originates from bank filtrate of a nearby losing stream. Water sampling campaigns in March and July 2012 confirmed the occurrence of artificial sweeteners at the investigated site. The municipal waste water treatment plant was identified as point-source for ACE in the river network. In the aquifer ACE was present in more than 80% of the monitoring wells. In addition, water samples were classified according to their hydrochemical composition, identifying two predominant types of water in the aquifer: (1) groundwater influenced by bank filtrate and (2) groundwater originating from local recharge. In combination with ACE concentrations a third type of water could be discriminated: (3) groundwater influence by bank filtrate but infiltrated prior to the waste water treatment plant. Moreover, the presence of ACE

  2. Preliminary delineation of natural geochemical reactions, Snake River Plain aquifer system, Idaho National Engineering Laboratory and vicinity, Idaho

    International Nuclear Information System (INIS)

    Knobel, L.L.; Bartholomay, R.C.; Orr, B.R.

    1997-05-01

    The U.S. Geological Survey, in cooperation with the U.S. Department of Energy, is conducting a study to determine the natural geochemistry of the Snake River Plain aquifer system at the Idaho National Engineering Laboratory (INEL), Idaho. As part of this study, a group of geochemical reactions that partially control the natural chemistry of ground water at the INEL were identified. Mineralogy of the aquifer matrix was determined using X-ray diffraction and thin-section analysis and theoretical stabilities of the minerals were used to identify potential solid-phase reactants and products of the reactions. The reactants and products that have an important contribution to the natural geochemistry include labradorite, olivine, pyroxene, smectite, calcite, ferric oxyhydroxide, and several silica phases. To further identify the reactions, analyses of 22 representative water samples from sites tapping the Snake River Plain aquifer system were used to determine the thermodynamic condition of the ground water relative to the minerals in the framework of the aquifer system. Principal reactions modifying the natural geochemical system include congruent dissolution of olivine, diopside, amorphous silica, and anhydrite; incongruent dissolution of labradorite with calcium montmorillonite as a residual product; precipitation of calcite and ferric oxyhydroxide; and oxidation of ferrous iron to ferric iron. Cation exchange reactions retard the downward movement of heavy, multivalent waste constituents where infiltration ponds are used for waste disposal

  3. Geohydrology and water quality of stratified-drift aquifers in the lower Merrimack and coastal river basins, southeastern New Hampshire

    Science.gov (United States)

    Stekl, Peter J.; Flanagan, Sarah M.

    1992-01-01

    Communities in the lower Merrimack River basin and coastal river basins of southeastern New Hampshire are experiencing increased demands for water because of a rapid increase in population. The population in 1987 was 225,495 and is expected to increase by 30 percent during the next decade. As of 1987, five towns used the stratified-drift aquifers for municipal supply and withdrew an estimated 6 million gallons per day. Four towns used the bedrock aquifer for municipal supply and withdrew an average of 1 .6 million gallons per day. Stratified-drift deposits cover 78 of the 327 square miles of the study area. These deposits are generally less than 10 square miles in areal extent, and their saturated thickness ranges front less than 20 feet to as much as 100 feet . Transinissivity exceeds 4,000 square feet per day in several locations. Stratified-drift aquifers in the eastern part are predominantly small ice-contact deposits surrounded by marine sediments or till of low hydraulic conductivity. Stratified-drift aquifers in the western part consist of ice-contact and proglacial deposits that are large in areal extent and are commonly in contact with surface-water bodies. Five stratified-drift aquifers, in the towns of Derry, Windham, Kingston, North Hampton, and Greenland, have the greatest potential to supply additional amounts of water. Potential yields and contributing areas of hypothetical supply wells were estimated for an aquifer in Windham near Cobbetts Pond and for an aquifer in Kingston along the Powwow River by use of a method analogous to superposition in conjunction with a numerical ground-waterflow model. The potential yield is estimated to be 0 .6 million gallons per day for the Windham-Cobbetts Pond aquifer and 4 .0 million gallons per day for the Kingston-Powwow River aquifer. Contributing recharge area for supply wells is estimated to be 1.6 square miles in the Windham-Cobbetts Pond aquifer and 4.9 square miles in the Kingston-Powwow River aquifer

  4. Consideration of Transient Stream/Aquifer Interaction with the Nonlinear Boussinesq Equation using HPM

    DEFF Research Database (Denmark)

    Ganji, S. S.; Barari, Amin; Sfahani, M. G.

    2011-01-01

    of time. The differential equations were solved using the method of Homotopy Perturbation. The simplicity and accuracy of the approximation are compared with “exact” solution and illustrated numerically and graphically. The results reveal that the HPM is very effective and simple and provides highly...... accurate solutions for nonlinear differential equations.......The phenomenon of stream–aquifer interaction was investigated via mathematical modeling using the Boussinesq equation. A new approximate solution of the one-dimensional Boussinesq equation is presented for a semi-infinite aquifer when the hydraulic head at the source is an arbitrary function...

  5. Yield and quality of ground water from stratified-drift aquifers, Taunton River basin, Massachusetts : executive summary

    Science.gov (United States)

    Lapham, Wayne W.; Olimpio, Julio C.

    1989-01-01

    Water shortages are a chronic problem in parts of the Taunton River basin and are caused by a combination of factors. Water use in this part of the Boston metropolitan area is likely to increase during the next decade. The Massachusetts Division of Water Resources projects that about 50% of the cities and towns within and on the perimeter of the basin may have water supply deficits by 1990 if water management projects are not pursued throughout the 1980s. Estimates of the long-term yield of the 26 regional aquifers indicate that the yields of the two most productive aquifers equal or exceed 11.9 and 11.3 cu ft/sec, 90% of the time, respectively, if minimum stream discharge is maintained at 99.5% flow duration. Eighteen of the 26 aquifers were pumped for public water supply during 1983. Further analysis of the yield characteristics of these 18 aquifers indicates that the 1983 pumping rate of each of these 18 aquifers can be sustained at least 70% of the time. Selected physical properties and concentrations of major chemical constituents in groundwater from the stratified-drift aquifers at 80 sampling sites were used to characterize general water quality in aquifers throughout the basin. The pH of the groundwater ranged from 5.4 to 7.0. Natural elevated concentrations of Fe and Mn in water in the stratified-drift aquifers are present locally in the basin. Natural concentrations of these two metals commonly exceed the limits of 0.3 mg/L for Fe and 0.05 mg/L for Mn recommended for drinking water. Fifty-one analyses of selected trace metals in groundwater samples from stratified-drift aquifers throughout the basin were used to characterize trace metal concentrations in the groundwater. Of the 10 constituents sampled that have US EPA limits recommended for drinking water, only the Pb concentration in water at one site (60 micrograms/L) exceeded the recommended limit of 50 micrograms/L. Analyses of selected organic compounds in water in the stratified-drift aquifers at 74

  6. Hydrogeology, groundwater levels, and generalized potentiometric-surface map of the Green River Basin lower Tertiary aquifer system, 2010–14, in the northern Green River structural basin

    Science.gov (United States)

    Bartos, Timothy T.; Hallberg, Laura L.; Eddy-Miller, Cheryl

    2015-07-14

    In cooperation with the Bureau of Land Management, groundwater levels in wells located in the northern Green River Basin in Wyoming, an area of ongoing energy development, were measured by the U.S. Geological Survey from 2010 to 2014. The wells were completed in the uppermost aquifers of the Green River Basin lower Tertiary aquifer system, which is a complex regional aquifer system that provides water to most wells in the area. Except for near perennial streams, groundwater-level altitudes in most aquifers generally decreased with increasing depth, indicating a general downward potential for groundwater movement in the study area. Drilled depth of the wells was observed as a useful indicator of depth to groundwater such that deeper wells typically had a greater depth to groundwater. Comparison of a subset of wells included in this study that had historical groundwater levels that were measured during the 1960s and 1970s and again between 2012 and 2014 indicated that, overall, most of the wells showed a net decline in groundwater levels.

  7. Evaluation of availability of water from drift aquifers near the Pomme de Terre and Chippewa rivers, western Minnesota

    Science.gov (United States)

    Delin, G.N.

    1987-01-01

    Ground-water flow in the confined- and unconfined-drift aquifers near Appleton and Benson, Minnesota, was simulated with a three-dimensional finite-difference ground-water-flow model. Model results indicate that 98 percent of the total inflow to the modeled area is from precipitation. Of the total outflow, 38 percent is ground-water discharge to the Pom me de Terre and Chippewa Rivers, 36 percent is evapotranspiration, 17 percent is ground-water pumpage, and 8 percent is ground-water discharge to the Minnesota River.

  8. Hydrologic conditions and distribution of selected radiochemical and chemical constituents in water, Snake River Plain aquifer, Idaho National Engineering Laboratory, Idaho, 1992 through 1995

    International Nuclear Information System (INIS)

    Bartholomay, R.C.; Tucker, B.J.; Ackerman, D.J.; Liszewski, M.J.

    1997-04-01

    Radiochemical and chemical wastewater discharged since 1952 to infiltration ponds and disposal wells at the Idaho National Engineering Laboratory (INEL) has affected water quality in the Snake River Plain aquifer. The US Geological Survey, in cooperation with the US Department of Energy, maintains a monitoring network at the INEL to determine hydrologic trends and to delineate the movement of radiochemical and chemical wastes in the aquifer. This report presents an analysis of water-level and water-quality data collected from the Snake River Plain aquifer during 1992--95

  9. Preliminary Analysis of the Role of Wetlands and Rivers in the Groundwater Discharge of the Guarani Aquifer System in NE Argentina

    International Nuclear Information System (INIS)

    Vives, L.; Rodriguez, L.; Manzano, M.; Valladares, A.; Agarwaal, P.; Araguas, L.

    2011-01-01

    The Guarani Aquifer System (GAS) is a transboundary aquifer occupying parts of Brazil, Uruguay, Paraguay and Argentina, covering some 1200000 km''2. The location and magnitude of recharge and the magnitude of regional discharges are uncertain. Regional groundwater flow modeling suggests that some discharge may occur through selected reaches of the Parana and Uruguay rivers and their tributaries, and perhaps, through the Ibera wetland system within Argentina. Preliminary findings of hydrochemical and isotopic sampling and analysis from surface water and groundwater in the Southern GAS region, studying the role of rivers and wetlands in the aquifer discharge and revising the conceptual model, are presented.

  10. Possible Links Among Iron Reduction, Silicate Weathering, and Arsenic Mobility in the Mississippi River Alluvial Aquifer in Louisiana

    Science.gov (United States)

    Borrok, D. M.; Lenz, R. M.; Jennings, J. E.; Gentry, M. L.; Vinson, D. S.

    2017-12-01

    The Lower Mississippi River Alluvial Aquifer (LMRAA) is a critical groundwater resource for Arkansas, Mississippi, and Louisiana. Part of the aquifer in Louisiana contains waters rich in Na, HCO3, Fe, and As. We hypothesize that CO2 generated from dissimilatory iron reduction (DIR) within the aquifer acts to weather Na-bearing silicates, contributing Na and HCO3, which may influence the mobility of As. We examined the geochemistry of the aquifer using historical and new data collected from the Louisiana Department of Environmental Quality (LDEQ). Major and trace element data were collected from about 25 wells in the LMRAA in Louisiana every three years from 2001-2016. Samples collected in 2016 were additionally analyzed for water isotopes and the δ13C of dissolved inorganic carbon (DIC). Results suggest that groundwater in the LMRAA can be broken into two broad categories, (1) water with a molar Na/Cl ratio near 1 and/or high salinity, and (2) water with excess Na (i.e., the molar concentration of Na is greater than that of Cl) that is often higher in alkalinity (up to 616 mg/L as CaCO3), Fe (up to 21 mg/L), and sometimes As (up to 67 µg/L). Concentrations of dissolved Fe were found to correlate, at least weakly, with alkalinity and Na excess. Six of the approximately 25 wells historically sampled consistently had concentrations of As >10 µg/L. These locations generally correspond with groundwater characterized by higher Fe, alkalinity, and Na-excess. Initial results for δD and δ18O suggest that more isotopically depleted waters are sourced from the Mississippi River, whereas local precipitation recharges the aquifer farther from the river (δ18O ranged from -7.5‰ to -3.5‰). Part of the δ13C-DIC variation (-17.4‰ to -10.6‰) is consistent with pH modification (6.5-7.7) along differing horizontal and vertical flow paths in the aquifer. This geochemistry appears to be controlled in part by geology. Areas nearer to the current Mississippi River where

  11. Hydrogeology and simulated groundwater flow and availability in the North Fork Red River aquifer, southwest Oklahoma, 1980–2013

    Science.gov (United States)

    Smith, S. Jerrod; Ellis, John H.; Wagner, Derrick L.; Peterson, Steven M.

    2017-09-28

    On September 8, 1981, the Oklahoma Water Resources Board established regulatory limits on the maximum annual yield of groundwater (343,042 acre-feet per year) and equal-proportionate-share (EPS) pumping rate (1.0 acre-foot per acre per year) for the North Fork Red River aquifer. The maximum annual yield and EPS were based on a hydrologic investigation that used a numerical groundwater-flow model to evaluate the effects of potential groundwater withdrawals on groundwater availability in the North Fork Red River aquifer. The Oklahoma Water Resources Board is statutorily required (every 20 years) to update the hydrologic investigation on which the maximum annual yield and EPS were based. Because 20 years have elapsed since the final order was issued, the U.S. Geological Survey, in cooperation with the Oklahoma Water Resources Board, conducted an updated hydrologic investigation and evaluated the effects of potential groundwater withdrawals on groundwater flow and availability in the North Fork Red River aquifer in Oklahoma. This report describes a hydrologic investigation of the North Fork Red River aquifer that includes an updated summary of the aquifer hydrogeology. As part of this investigation, groundwater flow and availability were simulated by using a numerical groundwater-flow model.The North Fork Red River aquifer in Beckham, Greer, Jackson, Kiowa, and Roger Mills Counties in Oklahoma is composed of about 777 square miles (497,582 acres) of alluvium and terrace deposits along the North Fork Red River and tributaries, including Sweetwater Creek, Elk Creek, Otter Creek, and Elm Fork Red River. The North Fork Red River is the primary source of surface-water inflow to Lake Altus, which overlies the North Fork Red River aquifer. Lake Altus is a U.S. Bureau of Reclamation reservoir with the primary purpose of supplying irrigation water to the Lugert-Altus Irrigation District.A hydrogeologic framework was developed for the North Fork Red River aquifer and included a

  12. Evidence for Upward Flow of Saline Water from Depth into the Mississippi River Valley Alluvial Aquifer in Southeastern Arkansas

    Science.gov (United States)

    Larsen, D.; Paul, J.

    2017-12-01

    Groundwater salinization is occurring in the Mississippi River Valley Alluvial (MRVA) aquifer in southeastern Arkansas (SE AR). Water samples from the MRVA aquifer in Chicot and Desha counties have yielded elevated Cl-concentrations with some as high as 1,639 mg/L. Considering that the MRVA aquifer is the principle source of irrigation water for the agricultural economy of SE AR, salinization needs to be addressed to ensure the sustainability of crop, groundwater, and soil resources in the area. The origin of elevated salinity in MRVA aquifer was investigated using spatial and factor analysis of historical water quality data, and sampling and tracer analysis of groundwater from irrigation, municipal, and flowing industrial wells in SE AR. Spatial analysis of Cl- data in relation to soil type, geomorphic features and sand-blow density indicate that the Cl- anomalies are more closely related to the sand-blow density than soil data, suggesting an underlying tectonic control for the distribution of salinity. Factor analysis of historical geochemical data from the MRVA and underlying Sparta aquifer shows dilute and saline groups, with saline groups weighted positively with Cl- or Na+ and Cl-. Tracer data suggest a component of evaporatively evolved crustal water of pre-modern age has mixed with younger, fresher meteoric sources in SE AR to create the saline conditions in the MRVA aquifer. Stable hydrogen and oxygen values of waters sampled from the Tertiary Sparta and MRVA aquifers deviate from the global and local meteoric water lines along an evaporative trend (slope=4.4) and mixing line with Eocene Wilcox Group groundwaters. Ca2+ and Cl- contents vary with Br- along mixing trends between dilute MRVA water and Jurassic Smackover Formation pore fluids in southern AR. Increasing Cl- content with C-14 age in MRVA aquifer groundwater suggests that the older waters are more saline. Helium isotope ratios decrease with He gas content for more saline water, consistent with

  13. Iodine-129 in the Snake River Plain Aquifer at and Near the Idaho National Laboratory, Idaho, 2003 and 2007

    Science.gov (United States)

    Bartholomay, Roy C.

    2009-01-01

    From 1953 to 1988, wastewater containing approximately 0.94 curies of iodine-129 (129I) was generated at the Idaho National Laboratory (INL) in southeastern Idaho. Almost all of this wastewater was discharged at or near the Idaho Nuclear Technology and Engineering Center (INTEC) on the INL site. Most of the wastewater was discharged directly into the eastern Snake River Plain aquifer through a deep disposal well until 1984; however, some wastewater also was discharged into unlined infiltration ponds or leaked from distribution systems below the INTEC. In 2003, the U.S. Geological Survey (USGS), in cooperation with the U.S. Department of Energy, collected samples for 129I from 36 wells used to monitor the Snake River Plain aquifer, and from one well used to monitor a perched zone at the INTEC. Concentrations of 129I in the aquifer ranged from 0.0000066 +- 0.0000002 to 0.72 +- 0.051 picocuries per liter (pCi/L). Many wells within a 3-mile radius of the INTEC showed decreases of as much as one order of magnitude in concentration from samples collected during 1990-91, and all of the samples had concentrations less than the Environmental Protection Agency's Maximum Contaminant Level (MCL) of 1 pCi/L. The average concentration of 129I in 19 wells sampled during both collection periods decreased from 0.975 pCi/L in 1990-91 to 0.249 pCi/L in 2003. These decreases are attributed to the discontinuation of disposal of 129I in wastewater after 1988 and to dilution and dispersion in the aquifer. Although water from wells sampled in 2003 near the INTEC showed decreases in concentrations of 129I compared with data collected in 1990-91, some wells south and east of the Central Facilities Area, near the site boundary, and south of the INL showed slight increases. These slight increases may be related to variable discharge rates of wastewater that eventually moved to these well locations as a mass of water from a particular disposal period. In 2007, the USGS collected samples for

  14. Hydrologic conditions and distribution of selected radiochemical and chemical constituents in water, Snake River Plain aquifer, Idaho National Engineering Laboratory, Idaho, 1989 through 1991

    International Nuclear Information System (INIS)

    Bartholomay, R.C.; Orr, B.R.; Liszewski, M.J.; Jensen, R.G.

    1995-08-01

    Radiochemical and chemical wastewater discharged since 1952 to infiltration ponds and disposal wells at the Idaho National Engineering Laboratory (INEL) has affected water quality in the Snake River Plain aquifer. The U.S. Geological Survey, in cooperation with the U.S. Department of Energy, maintains a continuous monitoring network at the INEL to determine hydrologic trends and to delineate the movement of radiochemical and chemical wastes in the aquifer. This report presents an analysis of water-level and water-quality data collected from the Snake River Plain aquifer during 1989-91. Water in the eastern Snake River Plain aquifer moves principally through fractures and interflow zones in basalt, generally flows southwestward, and eventually discharges at springs along the Snake River. The aquifer is recharged principally from irrigation water, infiltration of streamflow, and ground-water inflow from adjoining mountain drainage basins. Water levels in wells throughout the INEL generally declined during 1989-91 due to drought. Detectable concentrations of radiochemical constituents in water samples from wells in the Snake River Plain aquifer at the INEL decreased or remained constant during 1989-91. Decreased concentrations are attributed to reduced rates of radioactive-waste disposal, sorption processes, radioactive decay, and changes in waste-disposal practices. Detectable concentrations of chemical constituents in water from the Snake River Plain aquifer at the INEL were variable during 1989-91. Sodium and chloride concentrations in the southern part of the INEL increased slightly during 1989-91 because of increased waste-disposal rates and a lack of recharge from the Big Lost River. Plumes of 1,1,1-trichloroethane have developed near the Idaho Chemical Processing Plant and the Radioactive Waste Management Complex as a result of waste disposal practices

  15. Isotopic evidence for induced river recharge to the Dupi Tila aquifer in the Dhaka urban area, Bangladesh

    International Nuclear Information System (INIS)

    Darling, W.G.; Burgess, W.G.; Hasan, M.K.

    2002-01-01

    The population of the greater Dhaka metropolitan area is over 8 million and growing at a rate of six percent per year. Much of the water supply for the area is obtained from the underlying Dupi Tila sand aquifer. Intensive exploitation of the aquifer has led to a progressive decline in water levels beneath the parts of the city. The resulting cone of depression is thought likely to be causing the infiltration of surface water, largely from the polluted Buriganga waterway. The use of oxygen and hydrogen stable isotopes in unravelling the subsurface hydrology of the Dhaka area is hindered by the lack of data regarding 'baseline' conditions. Nevertheless it is clear from the evidence obtained from tubewells across the city that there is leakage from the Buriganga river extending several kilometres beneath parts of the urban area, possibly as far as the centre of the city. Carbon stable isotopes and major ion chemistry confirm this general picture; though appear to indicate that polluted river water has not penetrated quite so far towards the city centre. The Dupi Tila is regarded as a multi-layer aquifer on the basis of its hydrogeology and water quality variations with depth. Since there is little stable isotopic evidence for stratification, future investigations should include sensitive recent age indicators to investigate this, and the rates of groundwater movement in general. (author)

  16. Deciphering interaction of regional aquifers in Southern Tunisia using hydrochemistry and isotopic tools

    International Nuclear Information System (INIS)

    Abid, Kamel; Dulinski, Marek; Ammar, Friha Hadj; Rozanski, Kazimierz; Zouari, Kamel

    2012-01-01

    Groundwater is the most important source of water supply in southern Tunisia. Previous hydrogeologic and isotopic studies carried out in this region revealed the existence of two major aquifer systems: the “Complex Terminal” (CT) and the “Continental Intercalaire” (CI). Turonian carbonates constitute one of the major aquifer levels of the CT multilayered aquifer. It extends over most of southern Tunisia, and its hydrodynamic regime is largely influenced by tectonics, lithology and recharge conditions. Forty-eight groundwater samples from the CI and Turonian aquifers were collected between January and April 2004 for chemical and isotopic analyses. Hydrochemistry and isotopic tools were combined to get an insight into the processes controlling chemical composition of groundwater and wide-scale interaction of these two aquifer systems. Analysis of the dissolved constituents revealed that several processes control the observed chemical composition: (i) incongruent dissolution of carbonate minerals, (ii) dissolution of evaporitic minerals, and (iii) cation exchange. Dissolution alone cannot account for the observed high supersaturation states of groundwater with respect to calcite and dolomite. The observed supersaturation is most probably linked to geogenic CO 2 entering water-bearing horizons of the CT and CI aquifers via deep tectonic faults and discontinuities and subsequent degassing in the exploitation wells. Presence of geogenic CO 2 in the investigated region was confirmed by C isotope data of the DIC reservoir. The radiocarbon content of the Turonian samples varied between 9.5 and 43 pmc. For CI samples generally lower values were recorded, between 3.8 and 22.5 pmc. Stable isotope composition of Turonian groundwater samples varied from −8.3 to −5.3‰ for δ 18 O and from −60 to −25‰ for δ 2 H. The corresponding ranges of δ values for the Continental Intercalaire samples were from −8.9‰ to −6.9‰ for δ 18 O and from −68.2‰ to

  17. Optimizing Reservoir-Stream-Aquifer Interactions for Conjunctive Use and Hydropower Production

    Directory of Open Access Journals (Sweden)

    Hala Fayad

    2012-01-01

    Full Text Available Conjunctive management of water resources involves coordinating use of surface water and groundwater resources. Very few simulation/optimization (S-O models for stream-aquifer system management have included detailed interactions between groundwater, streams, and reservoir storage. This paper presents an S-O model doing that via artificial neural network simulators and genetic algorithm optimizer for multiobjective conjunctive water use problems. The model simultaneously addresses all significant flows including reservoir-stream-diversion-aquifer interactions in a more detailed manner than previous models. The model simultaneously maximizes total water provided and hydropower production. A penalty function implicitly poses constraints on state variables. The model effectively finds feasible optimal solutions and the Pareto optimum. Illustrated is application for planning water resource and minihydropower system development.

  18. Drinking Water Quality Criterion - Based site Selection of Aquifer Storage and Recovery Scheme in Chou-Shui River Alluvial Fan

    Science.gov (United States)

    Huang, H. E.; Liang, C. P.; Jang, C. S.; Chen, J. S.

    2015-12-01

    Land subsidence due to groundwater exploitation is an urgent environmental problem in Choushui river alluvial fan in Taiwan. Aquifer storage and recovery (ASR), where excess surface water is injected into subsurface aquifers for later recovery, is one promising strategy for managing surplus water and may overcome water shortages. The performance of an ASR scheme is generally evaluated in terms of recovery efficiency, which is defined as percentage of water injected in to a system in an ASR site that fulfills the targeted water quality criterion. Site selection of an ASR scheme typically faces great challenges, due to the spatial variability of groundwater quality and hydrogeological condition. This study proposes a novel method for the ASR site selection based on drinking quality criterion. Simplified groundwater flow and contaminant transport model spatial distributions of the recovery efficiency with the help of the groundwater quality, hydrological condition, ASR operation. The results of this study may provide government administrator for establishing reliable ASR scheme.

  19. Interaction of surface water and groundwater in the Nile River basin: isotopic and piezometric evidence

    Science.gov (United States)

    Kebede, Seifu; Abdalla, Osman; Sefelnasr, Ahmed; Tindimugaya, Callist; Mustafa, Osman

    2017-05-01

    Past discussions around water-resources management and development in the River Nile basin disregard groundwater resources from the equation. There is an increasing interest around factoring the groundwater resources as an integral part of the Nile Basin water resources. This is hampered by knowledge gap regarding the groundwater resources dynamics (recharge, storage, flow, quality, surface-water/groundwater interaction) at basin scale. This report provides a comprehensive analysis of the state of surface-water/groundwater interaction from the headwater to the Nile Delta region. Piezometric and isotopic (δ18O, δ2H) evidence reveal that the Nile changes from a gaining stream in the headwater regions to mostly a loosing stream in the arid lowlands of Sudan and Egypt. Specific zones of Nile water leakage to the adjacent aquifers is mapped using the two sources of evidence. Up to 50% of the surface-water flow in the equatorial region of the Nile comes from groundwater as base flow. The evidence also shows that the natural direction and rate of surface-water/groundwater interaction is largely perturbed by human activities (diversion, dam construction) particularly downstream of the Aswan High Dam in Egypt. The decrease in discharge of the Nile River along its course is attributed to leakage to the aquifers as well as to evaporative water loss from the river channel. The surface-water/groundwater interaction occurring along the Nile River and its sensitivity to infrastructure development calls for management strategies that account groundwater as an integral part of the Nile Basin resources.

  20. Effects of aquifer storage and recovery activities on water quality in the Little Arkansas River and Equus Beds Aquifer, south-central Kansas, 2011–14

    Science.gov (United States)

    Stone, Mandy L.; Garrett, Jessica D.; Poulton, Barry C.; Ziegler, Andrew C.

    2016-07-18

    The Equus Beds aquifer in south-central Kansas is aprimary water source for the city of Wichita. The Equus Beds aquifer storage and recovery (ASR) project was developed to help the city of Wichita meet increasing current (2016) and future water demands. The Equus Beds ASR project pumps water out of the Little Arkansas River during above-base flow conditions, treats it using drinking-water quality standards as a guideline, and recharges it into the Equus Beds aquifer for later use. Phase II of the Equus Beds ASR project currently (2016) includes a river intake facility and a surface-water treatment facility with a 30 million gallon per day capacity. Water diverted from the Little Arkansas River is delivered to an adjacent presedimentation basin for solids removal. Subsequently, waste from the surface-water treatment facility and the presedimentation basin is returned to the Little Arkansas River through a residuals return line. The U.S. Geological Survey, in cooperation with the city of Wichita, developed and implemented a hydrobiological monitoring program as part of the ASR project to characterize and quantify the effects of aquifer storage and recovery activities on the Little Arkansas River and Equus Beds aquifer water quality.Data were collected from 2 surface-water sites (one upstream and one downstream from the residuals return line), 1 residuals return line site, and 2 groundwater well sites (each having a shallow and deep part): the Little Arkansas River upstream from the ASR facility near Sedgwick, Kansas (upstream surface-water site 375350097262800), about 0.03 mile (mi) upstream from the residuals return line site; the Little Arkansas River near Sedgwick, Kans. (downstream surface-water site 07144100), about 1.68 mi downstream from the residuals return line site; discharge from the Little Arkansas River ASR facility near Sedgwick, Kansas (residuals return line site 375348097262800); 25S 01 W 07BCCC01 SMW–S11 near CW36 (MW–7 shallow groundwater well

  1. Aquifer recharge from infiltration basins in a highly urbanized area: the river Po Plain (Italy)

    Science.gov (United States)

    Masetti, M.; Nghiem, S. V.; Sorichetta, A.; Stevenazzi, S.; Santi, E. S.; Pettinato, S.; Bonfanti, M.; Pedretti, D.

    2015-12-01

    Due to the extensive urbanization in the Po Plain in northern Italy, rivers need to be managed to alleviate flooding problems while maintaining an appropriate aquifer recharge under an increasing percentage of impermeable surfaces. During the PO PLain Experiment field campaign in July 2015 (POPLEX 2015), both active and under-construction infiltration basins have been surveyed and analyzed to identify appropriate satellite observations that can be integrated to ground based monitoring techniques. A key strategy is to have continuous data time series on water presence and level within the basin, for which ground based monitoring can be costly and difficult to be obtained consistently.One of the major and old infiltration basin in the central Po Plain has been considered as pilot area. The basin is active from 2003 with ground based monitoring available since 2009 and supporting the development of a calibrated unsaturated-saturated two-dimensional numerical model simulating the infiltration dynamics through the basin.A procedure to use satellite data to detect surface water change is under development based on satellite radar backscatter data with an appropriate incidence angle and polarization combination. An advantage of satellite radar is that it can observe surface water regardless of cloud cover, which can be persistent during rainy seasons. Then, the surface water change is correlated to the reservoir water stage to determine water storage in the basin together with integrated ground data and to give quantitative estimates of variations in the local water cycle.We evaluated the evolution of the infiltration rate, to obtain useful insights about the general recharge behavior of basins that can be used for informed design and maintenance. Results clearly show when the basin becomes progressively clogged by biofilms that can reduce the infiltration capacity of the basin by as much as 50 times compared to when it properly works under clean conditions.

  2. Integrated frameworks for assessing and managing health risks in the context of managed aquifer recharge with river water.

    Science.gov (United States)

    Assmuth, Timo; Simola, Antti; Pitkänen, Tarja; Lyytimäki, Jari; Huttula, Timo

    2016-01-01

    Integrated assessment and management of water resources for the supply of potable water is increasingly important in light of projected water scarcity in many parts of the world. This article develops frameworks for regional-level waterborne human health risk assessment of chemical and microbiological contamination to aid water management, incorporating economic aspects of health risks. Managed aquifer recharge with surface water from a river in Southern Finland is used as an illustrative case. With a starting point in watershed governance, stakeholder concerns, and value-at-risk concepts, we merge common methods for integrative health risk analysis of contaminants to describe risks and impacts dynamically and broadly. This involves structuring analyses along the risk chain: sources-releases-environmental transport and fate-exposures-health effects-socio-economic impacts-management responses. Risks attributed to contaminants are embedded in other risks, such as contaminants from other sources, and related to benefits from improved water quality. A set of models along this risk chain in the case is presented. Fundamental issues in the assessment are identified, including 1) framing of risks, scenarios, and choices; 2) interaction of models and empirical information; 3) time dimension; 4) distributions of risks and benefits; and 5) uncertainties about risks and controls. We find that all these combine objective and subjective aspects, and involve value judgments and policy choices. We conclude with proposals for overcoming conceptual and functional divides and lock-ins to improve modeling, assessment, and management of complex water supply schemes, especially by reflective solution-oriented interdisciplinary and multi-actor deliberation. © 2015 SETAC.

  3. Dynamic surface water-groundwater exchange and nitrogen transport in the riparian aquifer of a tidal river

    Science.gov (United States)

    Sawyer, A. H.; Barnes, R.; Wallace, C.; Knights, D.; Tight, D.; Bayer, M.

    2017-12-01

    Tides in coastal rivers can propagate tens to hundreds of kilometers inland and drive large daily changes in water and nitrogen exchange across the sediment-water interface. We use field observations and numerical models to illuminate hydrodynamic controls on nitrogen export from the riparian aquifer to a fresh, tidal reach of White Clay Creek (Delaware, USA). In the banks, an aerobic zone with high groundwater nitrate concentrations occurs near the fluctuating water table. Continuous depth-resolved measurements of redox potential suggest that this zone is relatively stable over tidal timescales but moves up or down in response to storms. The main source of dissolved oxygen is soil air that is imbibed in the zone of water table fluctuations, and the source of nitrate is likely nitrification of ammonium produced locally from the mineralization of organic matter in floodplain soils. Much of the nitrate is removed by denitrification along oscillating flow paths towards the channel. Within centimeters of the sediment-water interface, denitrification is limited by the mixing of groundwater with oxygen-rich river water. Our models predict that the benthic zones of tidal rivers play an important role in removing new nitrate inputs from discharging groundwater but may be less effective at removing nitrate from river water. Nitrate removal and production rates are expected to vary significantly along tidal rivers as permeability, organic matter content, tidal range vary. It is imperative that we understand nitrogen dynamics along tidal rivers and their role in nitrogen export to the coast.

  4. Unravelling aquifer-wetland interaction using CSAMT and gravity methods: the Mollina-Camorra aquifer and the Fuente de Piedra playa-lake, southern Spain

    Science.gov (United States)

    Pedrera, A.; Martos-Rosillo, S.; Galindo-Zaldívar, J.; Rodríguez-Rodríguez, M.; Benavente, J.; Martín-Rodríguez, J. F.; Zúñiga-López, M. I.

    2016-06-01

    The hydrological regime of Fuente de Piedra playa-lake (Málaga, southern Spain) has been significantly affected by the intensive exploitation of groundwater in the area. The playa-lake is situated above clays, marls, and gypsum, and under unaltered conditions received surface-subsurface runoff within the watershed as well as groundwater discharge from two carbonate aquifers. We have analyzed the structure of the main one, the Mollina-Camorra carbonate aquifer, by combining controlled source audio magnetotellurics (CSAMT), gravity prospecting, and time-domain electromagnetic (TDEM) soundings. This geophysical information, together with new structural and hydrogeological data, was gathered to develop a new conceptual hydrogeological model. This model allows the hydrological linkage of the carbonate aquifer with the playa-lake system to be established. Moreover, the intensive exploitation in the carbonate aquifer, even outside the watershed of the playa-lake, has affected the hydrological regime of the system. This multidisciplinary work demonstrates the potential of geophysical methods for understanding wetland-aquifer interaction, having important groundwater management implications.

  5. Occurrence and geochemical behavior of arsenic in a coastal aquifer-aquitard system of the Pearl River Delta, China

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Ya [Department of Earth Sciences, The University of Hong Kong, Hong Kong (China); Jiao, Jiu Jimmy, E-mail: jjiao@hku.hk [Department of Earth Sciences, The University of Hong Kong, Hong Kong (China); Cherry, John A. [School of Engineering, University of Guelph, Guelph, ON, Canada N1G 2W1 (Canada)

    2012-06-15

    Elevated concentrations of arsenic, up to 161 {mu}g/L, have been identified in groundwater samples from the confined basal aquifer underlying the aquitard of the Pearl River Delta (PRD). Both aquatic arsenic in pore water and solid arsenic in the sediments in the basal aquifer and aquitard were identified. Arsenic speciation of groundwater in the basal aquifer was elucidated on a pH-Eh diagram. In the PRD, arsenic is enriched in groundwater having both low and high salinity, and arsenic enriched groundwater is devoid of dissolved oxygen, has negative Eh values, is slightly alkaline, and has abnormally high concentrations of ammonium and dissolved organic carbon, but low concentrations of nitrate and nitrite. Results of geochemical and hydrochemical analyses and sequential extraction analysis suggest that reductive dissolution of iron oxyhydroxide could be one of the important processes that mobilized solid arsenic. We speculate that mineralization of sedimentary organic matter could also contribute to aquatic arsenic. Scanning electron microscope analysis confirms that abundant authigenic pyrite is present in the sediments. Sulphate derived from paleo-seawater served as the important sulfur source for authigenic pyrite formation. Co-precipitation of arsenic with authigenic pyrite significantly controlled concentrations of aquatic arsenic in the coastal aquifer-aquitard system. - Highlights: Black-Right-Pointing-Pointer Coastal aquifer and aquitard are treated as an integrate system. Black-Right-Pointing-Pointer Both aquatic arsenic and solid arsenic are observed. Black-Right-Pointing-Pointer Aquatic arsenic is derived from reductive dissolution of iron oxyhydroxide. Black-Right-Pointing-Pointer Aquatic arsenic can also derived from mineralization of sedimentary organic matter. Black-Right-Pointing-Pointer Co-precipitation of arsenic with authigenic pyrite is significant in such a system.

  6. Characterising alluvial aquifers in a remote ephemeral catchment (Flinders River, Queensland) using a direct push tracer approach

    Science.gov (United States)

    Taylor, Andrew R.; Smith, Stanley D.; Lamontagne, Sébastien; Suckow, Axel

    2018-01-01

    The availability of reliable water supplies is a key factor limiting development in northern Australia. However, characterising groundwater resources in this remote part of Australia is challenging due to a lack of existing infrastructure and data. Here, direct push technology (DPT) was used to characterise shallow alluvial aquifers at two locations in the semiarid Flinders River catchment. DPT was used to evaluate the saturated thickness of the aquifer and estimate recharge rates by sampling for environmental tracers in groundwater (major ions, 2H, 18O, 3H and 14C). The alluvium at Fifteen Mile Reserve and Glendalough Station consisted of a mixture of permeable coarse sandy and gravely sediments and less permeable clays and silts. The alluvium was relatively thin (i.e. < 20 m) and, at the time of the investigation, was only partially saturated. Tritium (3H) concentrations in groundwater was ∼1 Tritium Unit (TU), corresponding to a mean residence time for groundwater of about 12 years. The lack of an evaporation signal for the 2H and 18O of groundwater suggests rapid localised recharge from overbank flood events as the primary recharge mechanism. Using the chloride mass balance technique (CMB) and lumped parameter models to interpret patterns in 3H in the aquifer, the mean annual recharge rate varied between 21 and 240 mm/yr. Whilst this recharge rate is relatively high for a semiarid climate, the alluvium is thin and heterogeneous hosting numerous alluvial aquifers with varied connectivity and limited storage capacity. Combining DPT and environmental tracers is a cost-effective strategy to characterise shallow groundwater resources in unconsolidated sedimentary aquifers in remote data sparse areas.

  7. Groundwater conservation and monitoring activities in the middle Brenta River plain (Veneto Region, Northern Italy: preliminary results about aquifer recharge

    Directory of Open Access Journals (Sweden)

    Andrea Sottani

    2014-09-01

    Full Text Available In the middle Brenta River plain there is a unconfined aquifer that represents an important groundwater resource in Veneto region. In this area the main groundwater recharge factor is related to the stream seepage: the water dispersion from the Brenta river is active with variable intensity from the foothill to the alignment Nove di Bassano - Cartigliano (Province of Vicenza. In order to mitigate the expected groundwater effects, due to future important waterworks withdrawals provided by the regional water resources management plans, an experimental project of Managed Aquifer Recharge has started, by means of the realization of some river transversal ramps. The construction of pilot works, partially completed, were preceded by a specific hydrogeological monitoring program, aimed to the evaluation of the effectiveness of the MAR actions in terms of comparison between pre-and post-operam conditions. Thanks to the development of a site-specific methodology, aimed to the quantification of the artificial infiltration rate, and after some years of monitoring controls of the hydrological and hydrogeological regimes, it is now possible to evaluate the extent and the rate of the recharge effects in groundwater due to ramps realization. The monitoring plan will be continued in the medium-long term. Some innovative approaches, based for example on the use of groundwater temperature measurements as recharge tracer, will help to validate the preliminary results.

  8. Evaluation of Managed Aquifer Recharge Scenarios using Treated Wastewater: a Case study of the Zarqa River Basin, Jordan

    Science.gov (United States)

    El-Rawy, Mustafa; Zlotnik, Vitaly; Al-Maktoumi, Ali; Al-Raggad, Marwan; Kacimov, Anvar; Abdalla, Osman

    2016-04-01

    Jordan is an arid country, facing great challenges due to limited water resources. The shortage of water resources constrains economy, especially agriculture that consumes the largest amount of available water (about 53 % of the total demand). According to the Jordan Water Strategy 2008 - 2022, groundwater is twice greater than the recharge rate. Therefore, the government charged the planners to consider treated wastewater (TWW) as a choice in the water resources management and development strategies. In Jordan, there are 31 TWW plants. Among them, As Samra plant serving the two major cities, Amman and Zarqa, is the largest, with projected maximum capacity of 135 Million m3/year. This plant is located upstream of the Zarqa River basin that accepts all TWW discharges. The Zarqa River is considered the most important source of surface water in Jordan and more than 78 % of its current is composed of TWW. The main objectives were to develop a conceptual model for a selected part of the Zarqa River basin, including the As Samrapant, and to provide insights to water resources management in the area using TWW. The groundwater flow model was developed using MODFLOW 2005 and used to assess changes in the aquifer and the Zarqa River under a set of different increments in discharge rates from the As Samra plant and different groundwater pumping rates. The results show that the water table in the study area underwent an average water table decline of 29 m prior to the As Samra plant construction, comparing with the current situation (with annual TWW discharge of 110 Million m3). The analysis of the TWW rate increase to 135 million m3/year (maximum capacity of the As Samra plant) shows that the average groundwater level will rise 0.55 m, compared to the current conditions. We found that the best practices require conjunctive use management of surface- and groundwater. The simulated scenarios highlight the significant role of TWW in augmenting the aquifer storage, improving

  9. Water quality of the Little Arkansas River and Equus Beds Aquifer before and concurrent with large-scale artificial recharge, south-central Kansas, 1995-2012

    Science.gov (United States)

    Tappa, Daniel J.; Lanning-Rush, Jennifer L.; Klager, Brian J.; Hansen, Cristi V.; Ziegler, Andrew C.

    2015-01-01

    The city of Wichita artificially recharged about 1 billion gallons of water into the Equus Beds aquifer during 2007–2012 as part of Phase I recharge of the Artificial Storage and Recovery project. This report, prepared in cooperation by the U.S. Geological Survey and the city of Wichita, Kansas, summarizes Little Arkansas River (source-water for artificial recharge) andEquus Beds aquifer water quality before (1995–2006) and during (2007–2012) Artificial Storage and Recovery Phase I recharge. Additionally, aquifer water-quality distribution maps are presented and water-quality changes associated with Phase I recharge timing are described.

  10. Estimation of hydraulic properties and development of a layered conceptual model for the Snake River plain aquifer at the Idaho National Engineering Laboratory, Idaho

    International Nuclear Information System (INIS)

    Frederick, D.B.; Johnson, G.S.

    1996-02-01

    The Idaho INEL Oversight Program, in association with the University of Idaho, Idaho Geological Survey, Boise State University, and Idaho State University, developed a research program to determine the hydraulic properties of the Snake River Plain aquifer and characterize the vertical distribution of contaminants. A straddle-packer was deployed in four observation wells near the Idaho Chemical Processing Plant at the Idaho National Engineering Laboratory. Pressure transducers mounted in the straddle-packer assembly were used to monitor the response of the Snake River Plain aquifer to pumping at the ICPP production wells, located 2600 to 4200 feet from the observation wells. The time-drawdown data from these tests were used to evaluate various conceptual models of the aquifer. Aquifer properties were estimated by matching time-drawdown data to type curves for partially penetrating wells in an unconfined aquifer. This approach assumes a homogeneous and isotropic aquifer. The hydraulic properties of the aquifer obtained from the type curve analyses were: (1) Storativity = 3 x 10 -5 , (2) Specific Yield = 0.01, (3) Transmissivity = 740 ft 2 /min, (4) Anisotropy (Kv:Kh)= 1:360

  11. Groundwater denitrification in two agricultural river catchments: influence of hydro-geological setting and aquifer geochemistry

    Science.gov (United States)

    McAleer, Eoin; Mellander, Per-Erik; Coxon, Catherine; Richards, Karl G.; Jahangir, Mohammad M. R.

    2015-04-01

    Identifying subsurface environments with a natural capacity for denitrification is important for improving agricultural management. At the catchment scale, a complex hierarchy of landscape, hydro-geological and physico-chemical characteristics combine to affect the distribution of groundwater nitrate (NO3-). This study was conducted along four instrumented hillslopes in two ca. 10km2 agricultural river catchments in Ireland, one dominated by arable and one by grassland agriculture. Both catchments are characterised by well drained soils, but have differing aquifer characteristics. The arable catchment is underlain by weathered Ordovician slate bedrock which is extensively fractured with depth. The grassland catchment is characterised by Devonian sandstone bedrock, exhibiting both lateral (from upslope to near stream) and vertical variations in permeability along each hillslope. The capacity for groundwater denitrification was assessed by examining the concentration and distribution patterns of N species (total nitrogen, nitrate, nitrite, ammonium), dissolved organic carbon (DOC), dissolved oxygen (DO) and redox potential (Eh) in monthly samples from shallow and deep groundwater piezometers (n=37). Additionally, the gaseous products of denitrification: nitrous oxide (N2O) and excess dinitrogen (excess N2) were measured seasonally using gas chromatography and membrane inlet mass spectroscopy, respectively. The slate catchment was characterised by uniformity, both laterally and vertically, in aquifer geochemistry and gaseous denitrification products. The four year spatial mean groundwater NO3--N concentration was 6.89 mg/l and exhibited low spatial and temporal variability (temporal SD: 1.19 mg/l, spatial SD: 1.185 mg/l). Elevated DO concentrations (mean: 9.75 mg/l) and positive Eh (mean: +176.5mV) at all sample horizons indicated a setting with little denitrification potential. This non-reducing environment was reflected in a low accumulation of denitrification

  12. Coupling a three-dimensional subsurface flow and transport model with a land surface model to simulate stream-aquifer-land interactions (CP v1.0)

    Science.gov (United States)

    Bisht, Gautam; Huang, Maoyi; Zhou, Tian; Chen, Xingyuan; Dai, Heng; Hammond, Glenn E.; Riley, William J.; Downs, Janelle L.; Liu, Ying; Zachara, John M.

    2017-12-01

    A fully coupled three-dimensional surface and subsurface land model is developed and applied to a site along the Columbia River to simulate three-way interactions among river water, groundwater, and land surface processes. The model features the coupling of the Community Land Model version 4.5 (CLM4.5) and a massively parallel multiphysics reactive transport model (PFLOTRAN). The coupled model, named CP v1.0, is applied to a 400 m × 400 m study domain instrumented with groundwater monitoring wells along the Columbia River shoreline. CP v1.0 simulations are performed at three spatial resolutions (i.e., 2, 10, and 20 m) over a 5-year period to evaluate the impact of hydroclimatic conditions and spatial resolution on simulated variables. Results show that the coupled model is capable of simulating groundwater-river-water interactions driven by river stage variability along managed river reaches, which are of global significance as a result of over 30 000 dams constructed worldwide during the past half-century. Our numerical experiments suggest that the land-surface energy partitioning is strongly modulated by groundwater-river-water interactions through expanding the periodically inundated fraction of the riparian zone, and enhancing moisture availability in the vadose zone via capillary rise in response to the river stage change. Meanwhile, CLM4.5 fails to capture the key hydrologic process (i.e., groundwater-river-water exchange) at the site, and consequently simulates drastically different water and energy budgets. Furthermore, spatial resolution is found to significantly impact the accuracy of estimated the mass exchange rates at the boundaries of the aquifer, and it becomes critical when surface and subsurface become more tightly coupled with groundwater table within 6 to 7 meters below the surface. Inclusion of lateral subsurface flow influenced both the surface energy budget and subsurface transport processes as a result of river-water intrusion into the

  13. Environmental isotope-aided studies on river water and groundwater interaction in the region of Seoul and Taegu

    International Nuclear Information System (INIS)

    Jong Sung Ahn

    1988-01-01

    Environmental isotope-aided studies on river water and groundwater interaction in the Han River Basin in areas especially occupied by crystalline rocks and limestone have been undertaken. The result indicates that the groundwater in the Seoul area is recharged by the Han River whereas in non-urban areas it is replenished by the infiltration of precipitation, the crystalline rock aquifers are recharged by downward percolation of shallow groundwater stored in overlying alluvium. Older groundwater having a very low concentration of tritium, ranging from 0 to 2 TU, was observed at the lower Han River basin near Bupyeong. It may indicate that the water sampled was recharged at a much earlier time than the other groundwater sampled, maybe, as early as the pre-thermonuclear period. The same interaction study conducted in the Karst area has shown that there is clearly no systematic differences of tritium level between surface water and groundwater and that the residence time of groundwater in limestone is very short, probably not longer than a few months. The areas recharged by the water from the overlying alluvium into the sedimentary rock aquifer were restricted only along the Kumho River channel and its tributaries in a clastic sedimentary rock area. Bedrock groundwater whose tritium level and stable isotope composition were less than 14 TU and -6.8 respectively was observed in the central part of Taegu city. (author). 15 refs, 21 figs, 8 tabs

  14. Groundwater-level analysis of selected wells in the Hoosic River Valley near Hoosick Falls, New York, for aquifer framework and properties

    Science.gov (United States)

    Williams, John H.; Heisig, Paul M.

    2018-03-05

    The U.S. Geological Survey, in cooperation with the New York State Department of Environmental Conservation, analyzed groundwater levels, drilling record logs, and field water-quality data from selected wells, and the surficial geology in the Hoosic River valley south of the village of Hoosick Falls, New York, to provide information about the framework and properties of a confined aquifer. The aquifer, which consists of ice-contact sand and gravel overlain by lacustrine clay and silt, was evaluated by the New York State Department of Environmental Conservation as part of their investigation of alternate water supplies for the village whose wellfield has been affected by perfluorooctanoic acid. Wells inventoried in the study area were classified as confined, water table, or transitional between the two aquifer conditions. Groundwater levels in three confined-aquifer wells and a transitional-aquifer well responded to pumping of a test production well finished in the confined aquifer. Groundwater levels in a water-table well showed no detectable water-level change in response to test-well pumping. Analysis of drawdown and recovery data from the three confined-aquifer wells and a transitional-aquifer well through the application of the Theis type-curve method provided estimates of aquifer properties. Representation of a constant-head boundary in the analysis where an unnamed pond and fluvial-terrace deposits abut the valley wall resulted in satisfactory matches of the Theis type curves with the observed water-level responses. Aquifer transmissivity estimates ranged from 1,160 to 1,370 feet squared per day. Aquifer storativity estimates ranged from 5.2×10–5 to 1.1×10–3 and were consistent with the inferred degree of confinement and distance from the represented recharge boundary.

  15. Integration of models of various types of aquifers for water quality management in the transboundary area of the Soča/Isonzo river basin (Slovenia/Italy).

    Science.gov (United States)

    Vižintin, Goran; Ravbar, Nataša; Janež, Jože; Koren, Eva; Janež, Naško; Zini, Luca; Treu, Francesco; Petrič, Metka

    2018-04-01

    Due to intrinsic characteristics of aquifers groundwater frequently passes between various types of aquifers without hindrance. The complex connection of underground water paths enables flow regardless of administrative boundaries. This can cause problems in water resources management. Numerical modelling is an important tool for the understanding, interpretation and management of aquifers. Useful and reliable methods of numerical modelling differ with regard to the type of aquifer, but their connections in a single hydrodynamic model are rare. The purpose of this study was to connect different models into an integrated system that enables determination of water travel time from the point of contamination to water sources. The worst-case scenario is considered. The system was applied in the Soča/Isonzo basin, a transboundary river in Slovenia and Italy, where there is a complex contact of karst and intergranular aquifers and surface flows over bedrock with low permeability. Time cell models were first elaborated separately for individual hydrogeological units. These were the result of numerical hydrological modelling (intergranular aquifer and surface flow) or complex GIS analysis taking into account the vulnerability map and tracer tests results (karst aquifer). The obtained cellular models present the basis of a contamination early-warning system, since it allows an estimation when contaminants can be expected to appear, and in which water sources. The system proves that the contaminants spread rapidly through karst aquifers and via surface flows, and more slowly through intergranular aquifers. For this reason, karst water sources are more at risk from one-off contamination incidents, while water sources in intergranular aquifers are more at risk in cases of long-term contamination. The system that has been developed is the basis for a single system of protection, action and quality monitoring in the areas of complex aquifer systems within or on the borders of

  16. To what extent do long-duration high-volume dam releases influence river–aquifer interactions? A case study in New South Wales, Australia

    KAUST Repository

    Graham, Peter W.; Andersen, M. S.; McCabe, Matthew; Ajami, Hoori; Baker, Andy R.; Acworth, I.

    2014-01-01

    from the aquifer to the river at rates of up to 1.6 m3/day per metre of bank. A groundwater-head prediction model was constructed and river–aquifer fluxes were calculated; however, predicted fluxes from this method showed poor correlation to fluxes

  17. Variations of uranium concentrations in a multi-aquifer system under the impact of surface water-groundwater interaction

    Science.gov (United States)

    Wu, Ya; Li, Junxia; Wang, Yanxin; Xie, Xianjun

    2018-04-01

    Understanding uranium (U) mobility is vital to minimizing its concentrations in potential drinking water sources. In this study, we report spatial-seasonal variations in U speciation and concentrations in a multi-aquifer system under the impact of Sanggan River in Datong basin, northern China. Hydrochemical and H, O, Sr isotopic data, thermodynamic calculations, and geochemical modeling are used to investigate the mechanisms of surface water-groundwater mixing-induced mobilization and natural attenuation of U. In the study site, groundwater U concentrations are up to 30.2 μg/L, and exhibit strong spatial-seasonal variations that are related to pH and Eh values, as well as dissolved Ca2+, HCO3-, and Fe(III) concentrations. For the alkaline aquifers of this site (pH 7.02-8.44), U mobilization is due to the formation and desorption of Ca2UO2(CO3)30 and CaUO2(CO3)32- caused by groundwater Ca2+ elevation via mineral weathering and Na-Ca exchange, incorporated U(VI) release from calcite, and U(IV) oxidation by Fe(OH)3. U immobilization is linked to the adsorption of CaUO2(CO3)32- and UO2(CO3)34- shifted from Ca2UO2(CO3)30 because of HCO3- elevation and Ca2+ depletion, U(VI) co-precipitation with calcite, and U(VI) reduction by adsorbed Fe2+ and FeS. Those results are of great significance for the groundwater resource management of this and similar other surface water-groundwater interaction zones.

  18. Relationships of stable isotopes, water-rock interaction and salinization in fractured aquifers, Petrolina region, Pernambuco State, Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Priscila Sousa, E-mail: priscila.silva@cprm.gov.br [Serviço Geológico do Brasil (CPRM), Manaus, AM (Brazil); Campos, José Eloi Guimarães; Cunha, Luciano Soares; Mancini, Luís Henrique, E-mail: eloi@unb.br, E-mail: lucianosc@unb.br, E-mail: lmancini@unb.br [Universidade de Brasília (UnB), Brasília, DF (Brazil)

    2018-01-15

    The Petrolina County, Pernambuco State, Brazil, presents specificities that make it unique from a hydrogeological point of view. Water resource scarcity is both a quantitative and qualitative issue. The climate is classified as semiarid, having low precipitation, along with high temperatures and evapotranspiration rates. Aquifer zones are related to low connected fractures resulting in a restricted water flow in the aquifer. The recharge is limited and the groundwater salinity is high. Stable isotope analyses of H and O were developed in groundwater samples (with different electrical conductivity) and surface water collected in a bypass channel flowing from the São Francisco River. The results were plotted in a δD ‰ versus δ{sup 18}O ‰ graph along with the curves of the global and local meteoric water line. Groundwater samples showed unexpected results showing a lighter sign pattern when compared to the meteoric waters. More negative δD and δ{sup 18}O values indicate an enrichment in light isotopes, which show that this process is not influenced by surface processes, where the enrichment occurs in heavy isotopes due to evaporation. The isotopic signature observed is interpreted either as resulting from the water-rock interaction, or as resulting from recharge from paleo rains. The waters are old and show restricted flow. So the water-rock contact time is extended. In the rock weathering processes, through the hydration of feldspars, there is preferential assimilation of heavy isotopes at the expense of the lighter ones that remain in the water. Analyses of the {sup 87}Sr/{sup 86}Sr ratio and isotopic groundwater dating assist in the interpretations. (author)

  19. Potentiometric Surface of the Upper Floridan Aquifer in the St. Johns River Water Management District and Vicinity, May 2008

    Science.gov (United States)

    Kinnaman, Sandra L.; Dixon, Joann F.

    2008-01-01

    This map depicts the potentiometric surface of the Upper Floridan aquifer in the St. Johns River Water Management District and vicinity for May 2008. Potentiometric contours are based on water-level measurements collected at 567 wells during the period May 6-May 27, near the end of the dry season. Some contours are inferred from previous potentiometric-surface maps with larger well networks. The potentiometric surface of the carbonate Upper Floridan aquifer responds mainly to rainfall, and more locally, to ground-water withdrawals and spring flow. Potentiometric-surface highs generally correspond to topographic highs where the aquifer is recharged. Springs and areas of diffuse upward leakage naturally discharge water from the aquifer and are most prevalent along the St. Johns River. Areas of discharge are reflected by depressions in the potentiometric surface. Ground-water withdrawals locally have lowered the potentiometric surface. Ground water in the Upper Floridan aquifer generally flows from potentiometric highs to potentiometric lows in a direction perpendicular to the contours. Measured values of the potentiometric surface ranged from 7 feet below NGVD29 near Fernandina Beach, Florida, to 124 feet above NGVD29 in Polk County, Florida. The average water level of the network in May 2008 was about 1 foot lower than the average in September 2007 following below-average rainfall during the dry season of 2007-08. Seasonal differences in network average water levels generally range from 4 to 6 feet. For 457 wells with previous measurements, May 2008 levels ranged from about 19 feet below to about 11 feet above September 2007 water levels. The average water level of the network in May 2008 was about 1 foot higher than the average in May 2007. For 544 wells with previous measurements, May 2008 levels ranged from about 8 feet below to about 13 feet above May 2007 water levels. Long-term hydrographs of ground-water levels for continuous and periodic wells are available

  20. Seasonal Influences on Ground-Surface Water Interactions in an Arsenic-Affected Aquifer in Cambodia

    Science.gov (United States)

    Richards, L. A.; Magnone, D.; Van Dongen, B.; Bryant, C.; Boyce, A.; Ballentine, C. J.; Polya, D. A.

    2015-12-01

    Millions of people in South and Southeast Asia consume drinking water daily which contains dangerous levels of arsenic exceeding health-based recommendations [1]. A key control on arsenic mobilization in aquifers in these areas has been controversially identified as the interaction of 'labile' organic matter contained in surface waters with groundwaters and sediments at depth [2-4], which may trigger the release of arsenic from the solid- to aqueous-phase via reductive dissolution of iron-(hyr)oxide minerals [5]. In a field site in Kandal Province, Cambodia, which is an arsenic-affected area typical to others in the region, there are strong seasonal patterns in groundwater flow direction, which are closely related to monsoonal rains [6] and may contribute to arsenic release in this aquifer. The aim of this study is to explore the implications of the high susceptibility of this aquifer system to seasonal changes on potential ground-surface water interactions. The main objectives are to (i) identify key zones where there are likely ground-surface water interactions, (ii) assess the seasonal impact of such interactions and (iii) quantify the influence of interactions using geochemical parameters (such as As, Fe, NO3, NH4, 14C, 3T/3He, δ18O, δ2H). Identifying the zones, magnitude and seasonal influence of ground-surface water interactions elucidates new information regarding potential locations/pathways of arsenic mobilization and/or transport in affected aquifers and may be important for water management strategies in affected areas. This research is supported by NERC (NE/J023833/1) to DP, BvD and CJB and a NERC PhD studentship (NE/L501591/1) to DM. References: [1] World Health Organization, 2008. [2] Charlet & Polya (2006), Elements, 2, 91-96. [3] Harvey et al. (2002), Science, 298, 1602-1606. [4] Lawson et al. (2013), Env. Sci. Technol. 47, 7085 - 7094. [5] Islam et al. (2004), Nature, 430, 68-71. [6] Benner et al. (2008) Appl. Geochem. 23(11), 3072 - 3087.

  1. Hydrogeological framework, numerical simulation of groundwater flow, and effects of projected water use and drought for the Beaver-North Canadian River alluvial aquifer, northwestern Oklahoma

    Science.gov (United States)

    Ryter, Derek W.; Correll, Jessica S.

    2016-01-14

    This report describes a study of the hydrology, hydrogeological framework, numerical groundwater-flow models, and results of simulations of the effects of water use and drought for the Beaver-North Canadian River alluvial aquifer, northwestern Oklahoma. The purpose of the study was to provide analyses, including estimating equal-proportionate-share (EPS) groundwater-pumping rates and the effects of projected water use and droughts, pertinent to water management of the Beaver-North Canadian River alluvial aquifer for the Oklahoma Water Resources Board.

  2. Organic and inorganic carbon dynamics in a karst aquifer: Santa Fe River Sink-Rise system, north Florida, USA

    Science.gov (United States)

    Jin, Jin; Zimmerman, Andrew R.; Moore, Paul J.; Martin, Jonathan B.

    2014-03-01

    Spatiotemporal variations in dissolved organic carbon (DOC), dissolved inorganic carbon (DIC), major ions concentrations and other geochemical parameters including stable carbon isotopes of DIC (δ13CDIC), were measured in surface water and deep and shallow well water samples of the Santa Fe River Sink-Rise eogenetic karst system, north Florida, USA. Three end-member water sources were identified: one DOC-rich/DIC-poor/δ13CDIC-depleted, one DOC-poor/DIC-rich/δ13CDIC-enriched, and one enriched in major ions. Given their spatiotemporal distributions, they were presumed to represent soil water, upper aquifer groundwater, and deep aquifer water sources, respectively. Using assumed ratios of Na+, Cl, and SO42- for each end-member, a mixing model calculated the contribution of each water source to each sample. Then, chemical effects of biogeochemical reactions were calculated as the difference between those predicted by the mixing model and measured species concentrations. In general, carbonate mineral dissolution occurred throughout the Sink-Rise system, surface waters were net autotrophic and the subsurface was in metabolic balance, i.e., no net DOC or DIC production or consumption. However, there was evidence for chemolithoautotrophy, perhaps by hydrogen oxidizing microbes, at some deep aquifer sites. Mineralization of this autochthonous natural dissolved organic matter (NDOM) led to localized carbonate dissolution as did surface water-derived NDOM supplied to shallow well sites during the highest flow periods. This study demonstrates linkages between hydrology, abiotic and microbial processes and carbon dynamics and has important implications for groundwater quality, karst morphologic evolution, and hydrogeologic projects such as aquifer storage and recovery in karst systems.

  3. Recharge and discharge areas of the Floridan Aquifer in the St. Johns River Water Management District and vicinity, Florida

    Science.gov (United States)

    Phelps, G.G.

    1984-01-01

    The Floridan aquifer is the principal source of most of the freshwater used in the St. Johns River Water Management District. An important step in managing water resources is the delineation of recharge and discharge areas. Geohydrologic factors to be considered when delineating recharge and discharge areas include: altitude and configuration of the potentiometric surface; direction and magnitude of the gradient between the water table and the potentiometric surface; and thickness and permeability of the overlying sediments. Recharge to the aquifer comes almost entirely from rainfall within the Water Management District. Significant recharge occurs where the aquifer is at or very near land surface, and where the overlying sediments are very permeable sand so that recharge takes place downward leakage. Recharge also occurs through sinkholes, sinkhole lakes, and other lakes that have a good connection to the aquifer. Major recharge areas are delineated on the map. Discharge occurs in areas of artesian flow (where the potentiometric surface is above land surface), primarily by diffuse upward leakage and by discharge from springs. Fifty-five springs, with total discharge of about 1,600 million gallons per day, are in the Water Management District. Areas of discharge and the location of springs are shown on the map. In 1980, total pumpage in the Water Management District was about 1,000 million gallons per day. Under predevelopment conditions, discharge by springs and upward leakage approximately balanced recharged. Additional discharge by pumpage may or may not be balanced by decreased spring discharge of increased downward leakage. Examination of long-term water level trends can indicate if recharge and discharge balance. Graphs of rainfall, water levels, and municipal pumpage for Jacksonville, Orlando, and Daytona Beach are shown on the map. (USGS)

  4. Ground-Water Budgets for the Wood River Valley Aquifer System, South-Central Idaho, 1995-2004

    Science.gov (United States)

    Bartolino, James R.

    2009-01-01

    The Wood River Valley contains most of the population of Blaine County and the cities of Sun Valley, Ketchum, Haley, and Bellevue. This mountain valley is underlain by the alluvial Wood River Valley aquifer system which consists of a single unconfined aquifer that underlies the entire valley, an underlying confined aquifer that is present only in the southernmost valley, and the confining unit that separates them. The entire population of the area depends on ground water for domestic supply, either from domestic or municipal-supply wells, and rapid population growth since the 1970s has caused concern about the long-term sustainability of the ground-water resource. To help address these concerns this report describes a ground-water budget developed for the Wood River Valley aquifer system for three selected time periods: average conditions for the 10-year period 1995-2004, and the single years of 1995 and 2001. The 10-year period 1995-2004 represents a range of conditions in the recent past for which measured data exist. Water years 1995 and 2001 represent the wettest and driest years, respectively, within the 10-year period based on precipitation at the Ketchum Ranger Station. Recharge or inflow to the Wood River Valley aquifer system occurs through seven main sources (from largest to smallest): infiltration from tributary canyons, streamflow loss from the Big Wood River, areal recharge from precipitation and applied irrigation water, seepage from canals and recharge pits, leakage from municipal pipes, percolation from septic systems, and subsurface inflow beneath the Big Wood River in the northern end of the valley. Total estimated mean annual inflow or recharge to the aquifer system for 1995-2004 is 270,000 acre-ft/yr (370 ft3/s). Total recharge for the wet year 1995 and the dry year 2001 is estimated to be 270,000 acre-ft/yr (370 ft3/s) and 220,000 acre-ft/yr (300 ft3/s), respectively. Discharge or outflow from the Wood River Valley aquifer system occurs through

  5. Characterization of the Gacka River basin karst aquifer (Croatia): Hydrochemistry, stable isotopes and tritium-based mean residence times

    Energy Technology Data Exchange (ETDEWEB)

    Ozyurt, Nur N. [Department of Geological Engineering, Hacettepe University, 06800 Ankara (Turkey); Lutz, Hans O. [Stable Isotope Laboratory, Medical Faculty, Rijeka University, 51000 Rijeka (Croatia); Faculty of Physics, Bielefeld University, 33615 Bielefeld (Germany); Hunjak, Tamara; Mance, Diana [Stable Isotope Laboratory, Medical Faculty, Rijeka University, 51000 Rijeka (Croatia); Roller-Lutz, Zvjezdana, E-mail: roller@medri.uniri.hr [Stable Isotope Laboratory, Medical Faculty, Rijeka University, 51000 Rijeka (Croatia)

    2014-07-01

    The Gacka River basin aquifer is a highly-developed karst system, located in the Croatian Dinarides. It is mostly composed of permeable Jurassic and Cretaceous carbonate rocks, and clastic sedimentary rocks of Paleogene age. Gacka River provides high quality water for the town of Otočac and several villages; together with the neighboring Lika River, the water is used for the Hydroelectric Power Plant at Senj on the coast. About 10 perennial and over 20 seasonal springs are located at 450 to 460 m a.s.l. (above sea level). Three major springs (Pećina, Majerovo and Tonkovića) provide 57% of the mean annual river flow. Similarities between the average groundwater temperatures as well as between the average specific electrical conductivity values (9.0 °C-328 μS/cm, 9.6 °C-350 μS/cm and 8.9 °C-312 μS/cm) of the springs imply that they are fed from aquifers with similar mean residence times (MRTs). The mean δ{sup 18}O contents of Majerovo, Tonkovića, and Pećina are around − 10.1‰, − 9.2‰ and − 8.9‰, respectively, revealing differences in the mean recharge area elevations. Compared to the temporal amplitude of the{sup 18}O signal of precipitation, the {sup 18}O signal variations of the springs are substantially attenuated because the recharges occurring at different times are well mixed within the aquifers. This indicates MRTs of more than just a few years. The average tritium contents of Pećina, Majerovo and Tonkovića are 5.48 TU, 6.13 TU and 6.17 TU, respectively. Serially connected exponential-plug type unsteady lumped-parameter models run on an annual time scale resulted in rather satisfactory matches between the observed and calculated tritium contents for all studied springs. The models revealed similar MRTs (and corresponding reservoir volumes) for Pećina, Tonkovića and Majerovo of 12 years (470 Mm{sup 3}), 12 years (1190 Mm{sup 3}), and 12.2 years (1210 Mm{sup 3}), respectively. Plug flow conditions dominate in about 90% of the total

  6. Hydrology, Water Quality, and Surface- and Ground-Water Interactions in the Upper Hillsborough River Watershed, West-Central Florida

    Science.gov (United States)

    Trommer, J.T.; Sacks, L.A.; Kuniansky, E.L.

    2007-01-01

    A study of the Hillsborough River watershed was conducted between October 1999 through September 2003 to characterize the hydrology, water quality, and interaction between the surface and ground water in the highly karstic uppermost part of the watershed. Information such as locations of ground-water recharge and discharge, depth of the flow system interacting with the stream, and water quality in the watershed can aid in prudent water-management decisions. The upper Hillsborough River watershed covers a 220-square-mile area upstream from Hillsborough River State Park where the watershed is relatively undeveloped. The watershed contains a second order magnitude spring, many karst features, poorly drained swamps, marshes, upland flatwoods, and ridge areas. The upper Hillsborough River watershed is subdivided into two major subbasins, namely, the upper Hillsborough River subbasin, and the Blackwater Creek subbasin. The Blackwater Creek subbasin includes the Itchepackesassa Creek subbasin, which in turn includes the East Canal subbasin. The upper Hillsborough River watershed is underlain by thick sequences of carbonate rock that are covered by thin surficial deposits of unconsolidated sand and sandy clay. The clay layer is breached in many places because of the karst nature of the underlying limestone, and the highly variable degree of confinement between the Upper Floridan and surficial aquifers throughout the watershed. Potentiometric-surface maps indicate good hydraulic connection between the Upper Floridan aquifer and the Hillsborough River, and a poorer connection with Blackwater and Itchepackesassa Creeks. Similar water level elevations and fluctuations in the Upper Floridan and surficial aquifers at paired wells also indicate good hydraulic connection. Calcium was the dominant ion in ground water from all wells sampled in the watershed. Nitrate concentrations were near or below the detection limit in all except two wells that may have been affected by

  7. Groundwater and surface-water interaction and effects of pumping in a complex glacial-sediment aquifer, phase 2, east-central Massachusetts

    Science.gov (United States)

    Eggleston, Jack R.; Zarriello, Phillip J.; Carlson, Carl S.

    2015-12-31

    The U.S. Geological Survey, in cooperation with the Town of Framingham, Massachusetts, has investigated the potential of proposed groundwater withdrawals at the Birch Road well site to affect nearby surface water bodies and wetlands, including Lake Cochituate, the Sudbury River, and the Great Meadows National Wildlife Refuge in east-central Massachusetts. In 2012, the U.S. Geological Survey developed a Phase 1 numerical groundwater model of a complex glacial-sediment aquifer to synthesize hydrogeologic information and simulate potential future pumping scenarios. The model was developed with MODFLOW-NWT, an updated version of a standard USGS numerical groundwater flow modeling program that improves solution of unconfined groundwater flow problems. The groundwater model and investigations of the aquifer improved understanding of groundwater–surface-water interaction and the effects of groundwater withdrawals on surface-water bodies and wetlands in the study area. The initial work also revealed a need for additional information and model refinements to better understand this complex aquifer system.

  8. Charaterising water-rock interaction in a mixed carbonate-evaporite karstified aquifer system, Qatar

    Science.gov (United States)

    Thirathititham, R.; Whitaker, F.

    2017-12-01

    Qatar is an arid country, most of the rainfall (80 mm/yr) occurring during intense storms. Surface runoff is endorheic and recharge is facilitated by karst features developed over an extended (c.30 Ma) period of exposure of the carbonate bedrock. In December 2016, we sampled a rare intense rainfall event (41 mm over 3 days), after which waters ponded within low-relief terminal depressions prior to infiltration. We compare the chemistry of these recharge waters with that of ground waters from 76 wells distributed across Qatar to understand the nature and spatial distribution of water-rock interaction. Using Cl- as a conservative tracer for seawater mixing, we calculate concentrations of rock-derived Ca2+, Mg2+ and SO42-. During surface detention, rain chemistry is modified by evaporation and interaction with clays and the surface bedrock over days to weeks. However, groundwater chemistry is dominated by subsurface interaction between recharge waters and the karstified Tertiary aquifers. These include the largely dolomitic Paleocene to Lower Eocene Umm er Radhuma (UER) and overlying Lower Eocene Rus, with the Middle Eocene Abarug limestone forming a locally important aquifer in the south west. Away from coastal areas which show clear evidence of salinisation, TDS of groundwaters in the interior of the peninsula increases from north to south. All groundwaters are significantly enriched in SO42-, but this enrichment is marked greater in the south. This likely reflects the presence of a unit of middle Rus gypsum that in the south of the country confines the Lower Rus and UER aquifers, whilst in the north either gypsum was not deposited or has been dissolved. Waters in the Abarug limestone show limited sulfate enrichment and a 1:1 molar ratio of rock-derived SO42-: Ca2+, but across much of the country both SO42- enrichment and SO42-: Ca2+ molar ratio are significantly higher, the latter reaching 2:1 and suggesting an additional sink for Ca2+. The dolomite aquifer waters

  9. Geochemistry of groundwater in the eastern Snake River Plain aquifer, Idaho National Laboratory and vicinity, eastern Idaho

    Science.gov (United States)

    Rattray, Gordon W.

    2018-05-30

    Nuclear research activities at the U.S. Department of Energy (DOE) Idaho National Laboratory (INL) in eastern Idaho produced radiochemical and chemical wastes that were discharged to the subsurface, resulting in detectable concentrations of some waste constituents in the eastern Snake River Plain (ESRP) aquifer. These waste constituents may pose risks to the water quality of the aquifer. In order to understand these risks to water quality the U.S. Geological Survey, in cooperation with the DOE, conducted a study of groundwater geochemistry to improve the understanding of hydrologic and chemical processes in the ESRP aquifer at and near the INL and to understand how these processes affect waste constituents in the aquifer.Geochemistry data were used to identify sources of recharge, mixing of water, and directions of groundwater flow in the ESRP aquifer at the INL. The geochemistry data were analyzed from 167 sample sites at and near the INL. The sites included 150 groundwater, 13 surface-water, and 4 geothermal-water sites. The data were collected between 1952 and 2012, although most data collected at the INL were collected from 1989 to 1996. Water samples were analyzed for all or most of the following: field parameters, dissolved gases, major ions, dissolved metals, isotope ratios, and environmental tracers.Sources of recharge identified at the INL were regional groundwater, groundwater from the Little Lost River (LLR) and Birch Creek (BC) valleys, groundwater from the Lost River Range, geothermal water, and surface water from the Big Lost River (BLR), LLR, and BC. Recharge from the BLR that may have occurred during the last glacial epoch, or paleorecharge, may be present at several wells in the southwestern part of the INL. Mixing of water at the INL primarily included mixing of surface water with groundwater from the tributary valleys and mixing of geothermal water with regional groundwater. Additionally, a zone of mixing between tributary valley water and

  10. Arsenic mobilization and attenuation by mineral-water interactions: implications for managed aquifer recharge.

    Science.gov (United States)

    Neil, Chelsea W; Yang, Y Jeffrey; Jun, Young-Shin

    2012-07-01

    Managed aquifer recharge (MAR) has potential for addressing deficits in water supplies worldwide. It is also widely used for preventing saltwater intrusion, maintaining the groundwater table, and augmenting ecological stream flows, among many other beneficial environmental applications. However, field MAR sites have experienced arsenic mobilization from aquifer formation minerals due to induced changes in groundwater chemistry. To address this environmental concern, it is crucial to understand the potential sources and sinks impacting arsenic mobilization. This paper outlines important mineral-water interactions that can occur at MAR sites. Detailed information on minerals of concern, physiochemical processes for arsenic mobilization or attenuation, and the potential impact of microbial activity and hydrology on these processes is provided. Based on these mineral-water interactions, guidelines for predicting arsenic mobility are presented, and recommendations are made concerning MAR site monitoring. The review emphasizes important aspects in correlating interfacial reactions to reactive transport modeling and elucidating future challenges, a first step toward developing safer and more sustainable MAR operations.

  11. Fully integrated physically-based numerical modelling of impacts of groundwater extraction on surface and irrigation-induced groundwater interactions: case study Lower River Murray, Australia

    Science.gov (United States)

    Alaghmand, S.; Beecham, S.; Hassanli, A.

    2013-07-01

    Combination of reduction in the frequency, duration and magnitude of natural floods, rising saline water-table in floodplains and excessive evapotranspiration have led to an irrigation-induced groundwater mound forced the naturally saline groundwater onto the floodplain in the Lower River Murray. It is during the attenuation phase of floods that these large salt accumulations are likely to be mobilised and will discharge into the river. The Independent Audit Group for Salinity highlighted this as the most significant risk in the Murray-Darling Basin. South Australian government and catchment management authorities have developed salt interception schemes (SIS). This is to pump the highly saline groundwater from the floodplain aquifer to evaporation basins in order to reduce the hydraulic gradient that drives the regional saline groundwater towards the River Murray. This paper investigates the interactions between a river (River Murray in South Australia) and a saline semi-arid floodplain (Clarks Floodplain) significantly influenced by groundwater lowering (Bookpurnong SIS). Results confirm that groundwater extraction maintain a lower water-table and more fresh river water flux to the saline floodplain aquifer. In term of salinity, this may lead to less amount of solute stored in the floodplain aquifer. This occurs through two mechanisms; extracting some of the solute mass from the system and changing the floodplain groundwater regime from a losing to gaining one. Finally, it is shown that groundwater extraction is able to remove some amount of solute stored in the unsaturated zone and mitigate the floodplain salinity risk.

  12. Cross-well slug testing in unconfined aquifers: A case study from the Sleepers River Watershed, Vermont

    Science.gov (United States)

    Belitz, K.; Dripps, W.

    1999-01-01

    Normally, slug test measurements are limited to the well in which the water level is perturbed. Consequently, it is often difficult to obtain reliable estimates of hydraulic properties, particularly if the aquifer is anisotropic or if there is a wellbore skin. In this investigation, we use partially penetrating stress and observation wells to evaluate specific storage, radial hydraulic conductivity and anisotropy of the aquifer, and the hydraulic conductivity of the borehole skin. The study site is located in the W9 subbasin of the Sleepers River Research Watershed, Vermont. At the site, ~3 m of saturated till are partially penetrated by a stress well located in the center of the unconfined aquifer and six observation wells located above, below, and at the depth of the stress well at radial distances of 1.2 and 2.4 m. The observation wells were shut in with inflatable packers. The semianalytical solution of Butler (1995) was used to conduct a sensitivity analysis and to interpret slug test results. The sensitivity analysis indicates that the response of the stress well is primarily sensitive to radial hydraulic conductivity, less sensitive to anisotropy and the conductivity of the borehole skin, and nearly insensitive to specific storage. In contrast, the responses of the observation wells are sensitive to all four parameters. Interpretation of the field data was facilitated by generating type curves in a manner analogous to the method of Cooper et al. (1967). Because the value of radial hydraulic conductivity is obtained from a match point, the number of unknowns is reduced to three. The estimated values of radial hydraulic conductivity and specific storage are comparable to those derived from the methods of Bouwer and Rice (1976) and Cooper et al. (1967). The values and skin conductivity, however, could not have been obtained without the use of observation wells.Normally, slug test measurements are limited to the well in which the water level is perturbed

  13. Iodine-129 in the eastern Snake River Plain aquifer at and near the Idaho National Laboratory, Idaho, 2010-12

    Science.gov (United States)

    Bartholomay, Roy C.

    2013-01-01

    From 1953 to 1988, approximately 0.941 curies of iodine-129 (129I) were contained in wastewater generated at the Idaho National Laboratory (INL) with almost all of this wastewater discharged at or near the Idaho Nuclear Technology and Engineering Center (INTEC). Most of the wastewater containing 129I was discharged directly into the eastern Snake River Plain (ESRP) aquifer through a deep disposal well until 1984; lesser quantities also were discharged into unlined infiltration ponds or leaked from distribution systems below the INTEC. During 2010–12, the U.S. Geological Survey in cooperation with the U.S. Department of Energy collected groundwater samples for 129I from 62 wells in the ESRP aquifer to track concentration trends and changes for the carcinogenic radionuclide that has a 15.7 million-year half-life. Concentrations of 129I in the aquifer ranged from 0.0000013±0.0000005 to 1.02±0.04 picocuries per liter (pCi/L), and generally decreased in wells near the INTEC, relative to previous sampling events. The average concentration of 129I in groundwater from 15 wells sampled during four different sample periods decreased from 1.15 pCi/L in 1990–91 to 0.173 pCi/L in 2011–12. All but two wells within a 3-mile radius of the INTEC showed decreases in concentration, and all but one sample had concentrations less than the U.S. Environmental Protection Agency maximum contaminant level of 1 pCi/L. These decreases are attributed to the discontinuation of disposal of 129I in wastewater and to dilution and dispersion in the aquifer. The decreases in 129I concentrations, in areas around INTEC where concentrations increased between 2003 and 2007, were attributed to less recharge near INTEC either from less flow in the Big Lost River or from less local snowmelt and anthropogenic sources. Although wells near INTEC sampled in 2011–12 showed decreases in 129I concentrations compared with previously collected data, some wells south and east of the Central Facilities Area

  14. Delineating groundwater/surface water interaction in a karst watershed: Lower Flint River Basin, southwestern Georgia, USA

    Directory of Open Access Journals (Sweden)

    Kathleen Rugel

    2016-03-01

    Full Text Available Study region: Karst watershed in Lower Flint River Basin (LFRB, southwestern Georgia, USA. Study focus: Baseflow discharges in the LFRB have declined for three decades as regional irrigation has increased; yet, the location and nature of connectivity between groundwater and surface water in this karstic region are poorly understood. Because growing water demands will likely be met by further development of regional aquifers, an important management concern is the nature of interactions between groundwater and surface water components under natural and anthropogenic perturbations. We conducted coarse and fine-scale stream sampling on a major tributary of the Lower Flint River (Ichawaynochaway Creek in southwestern Georgia, USA, to identify locations and patterns of enhanced hydrologic connectivity between this stream and the Upper Floridan Aquifer. New hydrological insights for the region: Prior water resource studies in the LFRB were based on regional modeling that neglected local heterogeneities in groundwater/surface water connectivity. Our results demonstrated groundwater inputs were concentrated around five of fifty sampled reaches, evidenced by increases in multiple groundwater indicators at these sites. These five reaches contributed up to 42% of the groundwater detected along the entire 50-km sampling section, with ∼24% entering through one groundwater-dominated tributary, Chickasawhatchee Creek. Intermittent flows occurred in two of these upstream reaches during extreme drought and heavy groundwater pumping, suggesting reach-scale behaviors should be considered in resource management and policy. Keywords: Karst hydrogeology, Hydrologic connectivity, Groundwater/surface water interaction, Upper Floridan Aquifer, Groundwater Irrigation

  15. Processes of water rock interaction in the Turonian aquifer of Oum Er-Rabia Basin, Morocco

    Science.gov (United States)

    Ettazarini, Said

    2005-12-01

    Possible water rock interaction processes, in the Moroccan basin of Oum Er-Rabia, were discussed by a geochemical study of groundwater from the Turonian limestone aquifer, the most important water resource in the region. Different types of water according to the classification of Piper were defined. Waters have shown an evolution from dominant CHO3 Ca Mg type through mixed to SO4 Cl Ca Mg type. The use of geochemical diagrams and chemical speciation modeling method has shown that water rock interaction is mainly controlled by carbonate and anhydrite dissolution, ion exchange and reverse ion exchange processes. Water rock equilibrium conditions are favorable for the precipitation of calcite, dolomite, kaolinite and magnesian smectite.

  16. Hydrogeochemical processes affecting the migration of radionuclides in a fluvial sand aquifer at the Chalk River Nuclear Laboratories

    International Nuclear Information System (INIS)

    Jackson, R.E.; Inch, K.J.

    1980-01-01

    In the mid-1950's two experimental disposals of liquid radioactive waste containing about 700 curries of strontium-90 and cesium-137 were made into pits in sandy ground at one of the disposal areas at Chalk River Nuclear Laboratories. Since then, the wastes have migrated into two nearby aquifers and have chromatographically separated into strontium-90 and cesium-137 plumes moving at velocities less than that of the transporting groundwater. Analysis of radioactively contaminated aquifer sediments showed that most of the strontium-90 is exchangeably adsorbed, primarily to feldspars and layer silicates (mainly biotite); the rest is either specifically adsorbed to iron (III) and perhaps manganese (IV) oxhydroxides or fixed to unknown sinks. Less than one half of adsorbed cesium-137 is exchangeable with 0.5 m calcium chloride; the high levels of cesium-137 adsorption and fixation are probably due to its reaction with micaceous minerals. Complexation of strontium-90 and cesium-137 does not appear to be an important factor affecting their transport or adsorption. In studies of groundwater quality or pollution, dissolved oxygen and sulfide should be measured in addition to the redox potential since it allows independent assessment of the redox levels. The latter were found to affect the mobility of multivalent transition metals and nonmetals. (DN)

  17. Identification of Hazardous Events for Drinking Water Production Process Using Managed Aquifer Recharge in the Nakdong River Delta, Korea

    International Nuclear Information System (INIS)

    Sang-Il, L.; Ji, H.W.

    2016-01-01

    Various hazardous events can cause chemical, microbial or physical hazards to a water supply system. The World Health Organization (WHO) and some countries have introduced the hazardous event analysis for identifying potential events which may be harmful to the safety of drinking water. This study extends the application of the hazardous event analysis into drinking water production using managed aquifer recharge (MAR). MAR is a way of using an aquifer to secure water resources by storing freshwater for future use and pumping it whenever necessary. The entire drinking water production process is subjected to the analysis from the catchment area to the consumer. Hazardous event analysis incorporates site-specific data as well as common issues occurring in the process of drinking water production. The hazardous events are classified based on chemical, microbial or physical characteristics. Likelihood and severity values are assigned, resulting in quantitative risk by multiplying them. The study site is located at a coastal area in the delta of the Nakdong River, South Korea. The site has suffered from salt water intrusion and surface water pollution from the water upstream. Nine major hazardous events were identified out of total 114 events from 10 drinking water production processes. These major hazardous events will provide useful information on what to be done to secure the water quality produced by a new water supply method. (author)

  18. Primary sink and source of geogenic arsenic in sedimentary aquifers in the southern Choushui River alluvial fan, Taiwan

    International Nuclear Information System (INIS)

    Lu, Kuang-Liang; Liu, Chen-Wuing; Wang, Sheng-Wei; Jang, Cheng-Shin; Lin, Kao-Hung; Liao, Vivian Hsiu-Chuan; Liao, Chung-Min; Chang, Fi-John

    2010-01-01

    This work characterized the sink and source/mobility of As in the As-affected sedimentary aquifers of the southern Choushui River alluvial fan, central Taiwan. Major mineral phases and chemical components were determined by XRD and X-ray photoelectron spectroscopy (XPS). The partitioning of As and Fe among cores were determined by sequential extraction. Based on XPS results, the primary forms of Fe were hematite, goethite and magnetite. Sequential extraction data and the XRF analysis indicated that Fe oxyhydroxides and sulfides were likely to be the major sinks of As, particularly in the distal-fan. Furthermore, Fe oxyhydroxides retained higher As contents than As-bearing sulfides. The reductive dissolution of Fe oxyhydroxides, which accompanied high levels of HCO 3 - and NH 4 + concentrations, was likely the principal release mechanism of As into groundwater in this area. The dual roles of Fe oxyhydroxides which are governed by the local redox condition act as a sink and source in the aquifer. Ionic replacement by PO 4 3- and HCO 3 - along with seasonal water table fluctuation, caused by monsoons and excessive pumping, contributed specific parts of As in the groundwater. The findings can be used to account for the inconsistency between Fe and As concentrations observed in groundwater.

  19. Geophysical logging studies in the Snake River Plain Aquifer at the Idaho National Engineering Laboratory: Wells 44, 45, and 46

    International Nuclear Information System (INIS)

    Morin, R.H.; Paillet, F.L.; Taylor, T.A.; Barrash, W.

    1993-01-01

    A geophysical logging program was undertaken to vertically profile changes in the hydrology and hydrochemistry of the Snake River Plain aquifer underlies the Idaho National Engineering Laboratory (INEL). Field investigations were concentrated within an area west of the Idaho Chemical Processing Plant (ICPP) in three wells that penetrated the upper 190 feet of the aquifer. The logs obtained in these wells consisted of temperature, caliper, nuclear (neutron porosity and gamma-gama density), natural gamma, borehole televiewer, gamma spectral, and thermal flowmeter (with and without pumping). The nuclear, caliper, and televiewer logs are used to delineate individual basalt flows or flow units and to recognize breaks between flows or flow units at interflow contact zones and sedimentary interbeds. The temperature logs and flowmeter measurements obtained under ambient hydraulic head conditions identified upward fluid-circulation patterns in the three wells. Gamma-spectral analyses performed at several depths in each well showed that the predominant source of gamma radiation in the formation at this site originates mainly from potassium ( 40 K). However, 137 Cesium was detected at 32 feet below land surface in well 45. An empirical investigation of the effect of source-receiver spacing on the response of the neutron-porosity logging tool was attempted in an effort to understand the conditions under which this tool might be applied to large-diameter boreholes in-unsaturated formations

  20. Developing a Composite Aquifer Vulnerability Assessment Model Combining DRASTIC with Agricultural Land Use in Choushui River Alluvial Fan, Central Taiwan

    Science.gov (United States)

    Chen, Shih-Kai; Hsieh, Chih-Heng; Tsai, Cheng-Bin

    2017-04-01

    Aquifer vulnerability assessment is considered to be an effective tool in controlling potential pollution which is critical for groundwater management. The Choushui River alluvial fan, located in central Taiwan, is an agricultural area with complex crop patterns and various irrigation schemes, which increased the difficulties in groundwater resource management. The aim of this study is to propose an integrated methodology to assess shallow groundwater vulnerability by including land-use impact on groundwater potential pollution. The original groundwater vulnerability methodology, DRASTIC, was modified by adding a land-use parameter in order to assess groundwater vulnerability under intense agricultural activities. To examine the prediction capacity of pollution for the modified DRASTIC model, various risk categories of contamination potentials were compared with observed nitrate-N obtained from groundwater monitoring network. It was found that for the original DRASTIC vulnerability map, some areas with low nitrate-N concentrations are covered within the high vulnerability areas, especially in the northern part of mid-fan areas, where rice paddy is the main crop and planted for two crop seasons per year. The low nitrate-N contamination potential of rice paddies may be resulted from the denitrification in the reduced root zone. By reducing the rating for rice paddies, the modified model was proved to be capable of increasing the precise of prediction in study area. The results can provide a basis for groundwater monitoring network design and effective preserve measures formulation in the mixed agricultural area. Keyword:Aquifer Vulnerability, Groundwater, DRASTIC, Nitrate-N

  1. Contaminant transport in the Snake River Plain Aquifer: Phase 1, Part 1: Simple analytical model of individual plumes

    International Nuclear Information System (INIS)

    Rood, A.S.; Arnett, R.C.; Barraclough, J.T.

    1989-05-01

    A preliminary, semi-quantitative assessment of the migration of INEL effluents in the Snake River Plain Aquifer (SRPA) was performed. This study focused on past tritium, 129 I, and 90 Sr effluents from the Idaho Chemical Processing Plant (ICPP) and Test Reactor Area (TRA) and carbon tetrachloride from the Radioactive Waste Management Complex (RWMC). The disposal ponds at TRA and the ICPP injection well were the primary means of liquid radioactive waste discharge from the ICPP and TRA. Drums containing solidified chlorinated solvents disposed of at the RWMC were the primary source of carbon tetrachloride. Water samples taken from wells located in the SRPA show detectable quantities of the four contaminants. The predicted radionuclide concentrations exceed drinking water limits in limited areas within the INEL boundaries. Without planned remedial action, carbon tetrachloride is predicted to exceed drinking water limits beyond the site boundaries near the middle of the next century. 16 refs., 23 figs., 3 tabs

  2. Groundwater-quality data from the eastern Snake River Plain Aquifer, Jerome and Gooding Counties, south-central Idaho, 2017

    Science.gov (United States)

    Skinner, Kenneth D.

    2018-05-11

    Groundwater-quality samples and water-level data were collected from 36 wells in the Jerome/Gooding County area of the eastern Snake River Plain aquifer during June 2017. The wells included 30 wells sampled for the U.S. Geological Survey’s National Water-Quality Assessment project, plus an additional 6 wells were selected to increase spatial distribution. The data provide water managers with the ability for an improved understanding of groundwater quality and flow directions in the area. Groundwater-quality samples were analyzed for nutrients, major ions, trace elements, and stable isotopes of water. Quality-assurance and quality-control measures consisted of multiple blank samples and a sequential replicate sample. All data are available online at the USGS National Water Information System.

  3. An Assessment of Regional Water Resources and Agricultural Sustainability in the Mississippi River Alluvial Aquifer System of Mississippi and Arkansas Under Current and Future Climate

    Science.gov (United States)

    Rigby, J.; Reba, M.

    2011-12-01

    The Lower Mississippi River Alluvial Plain is a highly productive agricultural region for rice, soy beans, and cotton that depends heavily on irrigation. Development of the Mississippi River Alluvial Aquifer (MRAA), one of the more prolific agricultural aquifers in the country, has traditionally been the primary source for irrigation in the region yielding over 1,100 Mgal/day to irrigation wells. Increasingly, the realities of changing climate and rapidly declining water tables have highlighted the necessity for new water management practices. Tail-water recovery and reuse is a rapidly expanding practice due in part to the efforts and cost-sharing of the NRCS, but regional studies of the potential for such practices to alleviate groundwater mining under current and future climate are lacking. While regional studies of aquifer geology have long been available, including assessments of regional groundwater flow, much about the aquifer is still not well understood including controls on recharge rates, a crucial component of water management design. We review the trends in regional availability of surface and groundwater resources, their current status, and the effects of recent changes in management practices on groundwater decline in Mississippi and Arkansas. Global and regional climate projections are used to assess scenarios of sustainable aquifer use under current land use and management along with the potential for more widely practiced surface water capture and reuse to alleviate groundwater decline. Finally, we highlight crucial knowledge gaps and challenges associated with the development of water management practices for sustainable agricultural use in the region.

  4. Hydrogeology of confined-drift aquifers near the Pomme de Terre and Chippewa rivers, western Minnesota

    Science.gov (United States)

    Delin, G.N.

    1986-01-01

    Confined-drift aquifers in a 1,380-square-mile area of western Minnesota range in thickness from less than 10 feet to 114 feet. Transmissivities range from less than 1,000 square feet per day to over 16,000 square feet per day and theoretical well yields range from less than 100 gallons per minute to more than 1,800 gallons per minute.

  5. Origin and availability of organic matter leading to arsenic mobilisation in aquifers of the Red River Delta, Vietnam

    International Nuclear Information System (INIS)

    Eiche, Elisabeth; Berg, Michael; Hönig, Sarah-Madeleine; Neumann, Thomas; Lan, Vi Mai; Pham, Thi Kim Trang; Pham, Hung Viet

    2017-01-01

    Groundwater arsenic (As) concentrations in the Red River Delta (Vietnam) are often patchy and related to the microbially induced reduction of Fe oxy-hydroxides. In this study, we explored the influence of the origin, composition and availability of natural organic matter on the hydrochemical variability in the aquifers of Van Phuc. Carbon isotope signatures (δ"1"3C_o_r_g) and C/N ratios were assessed in combination with lithology, geochemistry, hydrochemistry, hydrology and the distribution of specific biomarkers. The elationship of C/N ratios and δ"1"3C_o_r_g distinguished four groups of sediment types that differ in their organic carbon sources. This includes organic carbon originating predominantly from vascular C_3 plants (C/N: 15.4–21.0, δ"1"3C_o_r_g: −28.6 to −26.7‰), C_4 plants (C/N: 10.6; δ"1"3C_o_r_g: −14.8‰), freshwater derived particulate organic carbon (C/N: ≤8; δ"1"3C_o_r_g:≤−24‰) as well as mixtures incorporating both sources. At the high As sites, we found particulate organic carbon (POC) being 1–2‰ less depleted in δ"1"3C_o_r_g than at low As sites. More importantly, however, our assessment shows that, the availability of organic matter has to be considered decisive with regard to groundwater As contamination. Fine-grained clayey sediments overlaying sands generally protect organic matter from substantial degradation and its leaching into an adjacent aquifer. However, at the sites that are high in dissolved As in Van Phuc, sediment layers rich in organic matter are hydraulically connected to the underlying aquifer. Here, soluble organic matter seeping into the aquifer can induce and/or enhance reducing conditions, thereby mobilising As from Fe oxy-hydroxides. Our study shows that both the clay content as well as the origin of organic matter are largely controlled by the depositional environment of the sediments. - Highlights: • Particulate organic carbon (POC) from C_3/C_4 plants and freshwater is a main source of

  6. Quality of Shallow Groundwater and Drinking Water in the Mississippi Embayment-Texas Coastal Uplands Aquifer System and the Mississippi River Valley Alluvial Aquifer, South-Central United States, 1994-2004

    Science.gov (United States)

    Welch, Heather L.; Kingsbury, James A.; Tollett, Roland W.; Seanor, Ronald C.

    2009-01-01

    The Mississippi embayment-Texas coastal uplands aquifer system is an important source of drinking water, providing about 724 million gallons per day to about 8.9 million people in Texas, Louisiana, Mississippi, Arkansas, Missouri, Tennessee, Kentucky, Illinois, and Alabama. The Mississippi River Valley alluvial aquifer ranks third in the Nation for total withdrawals of which more than 98 percent is used for irrigation. From 1994 through 2004, water-quality samples were collected from 169 domestic, monitoring, irrigation, and public-supply wells in the Mississippi embayment-Texas coastal uplands aquifer system and the Mississippi River Valley alluvial aquifer in various land-use settings and of varying well capacities as part of the U.S. Geological Survey's National Water-Quality Assessment Program. Groundwater samples were analyzed for physical properties and about 200 water-quality constituents, including total dissolved solids, major inorganic ions, trace elements, radon, nutrients, dissolved organic carbon, pesticides, pesticide degradates, and volatile organic compounds. The occurrence of nutrients and pesticides differed among four groups of the 114 shallow wells (less than or equal to 200 feet deep) in the study area. Tritium concentrations in samples from the Holocene alluvium, Pleistocene valley trains, and shallow Tertiary wells indicated a smaller component of recent groundwater than samples from the Pleistocene terrace deposits. Although the amount of agricultural land overlying the Mississippi River Valley alluvial aquifer was considerably greater than areas overlying parts of the shallow Tertiary and Pleistocene terrace deposits wells, nitrate was rarely detected and the number of pesticides detected was lower than other shallow wells. Nearly all samples from the Holocene alluvium and Pleistocene valley trains were anoxic, and the reducing conditions in these aquifers likely result in denitrification of nitrate. In contrast, most samples from the

  7. Application of hydrologic tools and monitoring to support managed aquifer recharge decision making in the Upper San Pedro River, Arizona, USA

    Science.gov (United States)

    Lacher, Laurel J.; Turner, Dale S.; Gungle, Bruce W.; Bushman, Brooke M.; Richter, Holly E.

    2014-01-01

    The San Pedro River originates in Sonora, Mexico, and flows north through Arizona, USA, to its confluence with the Gila River. The 92-km Upper San Pedro River is characterized by interrupted perennial flow, and serves as a vital wildlife corridor through this semiarid to arid region. Over the past century, groundwater pumping in this bi-national basin has depleted baseflows in the river. In 2007, the United States Geological Survey published the most recent groundwater model of the basin. This model served as the basis for predictive simulations, including maps of stream flow capture due to pumping and of stream flow restoration due to managed aquifer recharge. Simulation results show that ramping up near-stream recharge, as needed, to compensate for downward pumping-related stress on the water table, could sustain baseflows in the Upper San Pedro River at or above 2003 levels until the year 2100 with less than 4.7 million cubic meters per year (MCM/yr). Wet-dry mapping of the river over a period of 15 years developed a body of empirical evidence which, when combined with the simulation tools, provided powerful technical support to decision makers struggling to manage aquifer recharge to support baseflows in the river while also accommodating the economic needs of the basin.

  8. Application of Hydrologic Tools and Monitoring to Support Managed Aquifer Recharge Decision Making in the Upper San Pedro River, Arizona, USA

    Directory of Open Access Journals (Sweden)

    Laurel J. Lacher

    2014-11-01

    Full Text Available The San Pedro River originates in Sonora, Mexico, and flows north through Arizona, USA, to its confluence with the Gila River. The 92-km Upper San Pedro River is characterized by interrupted perennial flow, and serves as a vital wildlife corridor through this semiarid to arid region. Over the past century, groundwater pumping in this bi-national basin has depleted baseflows in the river. In 2007, the United States Geological Survey published the most recent groundwater model of the basin. This model served as the basis for predictive simulations, including maps of stream flow capture due to pumping and of stream flow restoration due to managed aquifer recharge. Simulation results show that ramping up near-stream recharge, as needed, to compensate for downward pumping-related stress on the water table, could sustain baseflows in the Upper San Pedro River at or above 2003 levels until the year 2100 with less than 4.7 million cubic meters per year (MCM/yr. Wet-dry mapping of the river over a period of 15 years developed a body of empirical evidence which, when combined with the simulation tools, provided powerful technical support to decision makers struggling to manage aquifer recharge to support baseflows in the river while also accommodating the economic needs of the basin.

  9. Modelling free surface aquifers to analyze the interaction between groundwater and sinuous streams

    DEFF Research Database (Denmark)

    Balbarini, Nicola; Boon, W. M.; Bjerg, Poul Løgstrup

    and errors. In addition, when streams are sinuous, groundwater flow is truly 3-dimensional, with strong vertical flows and sharp changes in horizontal direction. Here 3 different approaches to simulating free surface aquifers are compared for simulating groundwater-stream interaction. The aim of the models......: a saturated-unsaturated flow model, moving mesh, and a new coordinate transformation. The saturated/unsaturated model couples the saturated groundwater flow equation with a solution of Richards equation. The moving mesh solves the saturated groundwater equation with a free surface and deformable numerical...... finite element mesh. Finally, the new coordinate transform method employs a coordinate transform so that the saturated groundwater flow equation is solved on a fixed finite element mesh with a stationary free surface. This paper describes in detail the new coordinate transform method. It employs...

  10. Using SWAT-MODFLOW to simulate groundwater flow and groundwater-surface water interactions in an intensively irrigated stream-aquifer system

    Science.gov (United States)

    Wei, X.; Bailey, R. T.

    2017-12-01

    Agricultural irrigated watersheds in semi-arid regions face challenges such as waterlogging, high soil salinity, reduced crop yield, and leaching of chemical species due to extreme shallow water tables resulting from long-term intensive irrigation. Hydrologic models can be used to evaluate the impact of land management practices on water yields and groundwater-surface water interactions in such regions. In this study, the newly developed SWAT-MODFLOW, a coupled surface/subsurface hydrologic model, is applied to a 950 km2 watershed in the Lower Arkansas River Valley (southeastern Colorado). The model accounts for the influence of canal diversions, irrigation applications, groundwater pumping, and earth canal seepage losses. The model provides a detailed description of surface and subsurface flow processes, thereby enabling detailed description of watershed processes such as runoff, infiltration, in-streamflow, three-dimensional groundwater flow in a heterogeneous aquifer system with sources and sinks (e.g. pumping, seepage to subsurface drains), and spatially-variable surface and groundwater exchange. The model was calibrated and tested against stream discharge from 5 stream gauges in the Arkansas River and its tributaries, groundwater levels from 70 observation wells, and evapotranspiration (ET) data estimated from satellite (ReSET) data during the 1999 to 2007 period. Since the water-use patterns within the study area are typical of many other irrigated river valleys in the United States and elsewhere, this modeling approach is transferable to other regions.

  11. Development of a stream–aquifer numerical flow model to assess river water management under water scarcity in a Mediterranean basin

    International Nuclear Information System (INIS)

    Mas-Pla, Josep; Font, Eva; Astui, Oihane; Menció, Anna; Rodríguez-Florit, Agustí; Folch, Albert; Brusi, David; Pérez-Paricio, Alfredo

    2012-01-01

    Stream flow, as a part of a basin hydrological cycle, will be sensible to water scarcity as a result of climate change. Stream vulnerability should then be evaluated as a key component of the basin water budget. Numerical flow modeling has been applied to an alluvial formation in a small mountain basin to evaluate the stream–aquifer relationship under these future scenarios. The Arbúcies River basin (116 km 2 ) is located in the Catalan Inner Basins (NE Spain) and its lower reach, which is related to an alluvial aquifer, usually becomes dry during the summer period. This study seeks to determine the origin of such discharge losses whether from natural stream leakage and/or induced capture due to groundwater withdrawal. Our goal is also investigating how discharge variations from the basin headwaters, representing potential effects of climate change, may affect stream flow, aquifer recharge, and finally environmental preservation and human supply. A numerical flow model of the alluvial aquifer, based on MODFLOW and especially in the STREAM routine, reproduced the flow system after the usual calibration. Results indicate that, in the average, stream flow provides more than 50% of the water inputs to the alluvial aquifer, being responsible for the amount of stored water resources and for satisfying groundwater exploitation for human needs. Detailed simulations using daily time-steps permit setting threshold values for the stream flow entering at the beginning of the studied area so surface discharge is maintained along the whole watercourse and ecological flow requirements are satisfied as well. The effects of predicted rainfall and temperature variations on the Arbúcies River alluvial aquifer water balance are also discussed from the outcomes of the simulations. Finally, model results indicate the relevance of headwater discharge management under future climate scenarios to preserve downstream hydrological processes. They also point out that small mountain basins

  12. Surface complexation modeling of groundwater arsenic mobility: Results of a forced gradient experiment in a Red River flood plain aquifer, Vietnam

    Science.gov (United States)

    Jessen, Søren; Postma, Dieke; Larsen, Flemming; Nhan, Pham Quy; Hoa, Le Quynh; Trang, Pham Thi Kim; Long, Tran Vu; Viet, Pham Hung; Jakobsen, Rasmus

    2012-12-01

    Three surface complexation models (SCMs) developed for, respectively, ferrihydrite, goethite and sorption data for a Pleistocene oxidized aquifer sediment from Bangladesh were used to explore the effect of multicomponent adsorption processes on As mobility in a reduced Holocene floodplain aquifer along the Red River, Vietnam. The SCMs for ferrihydrite and goethite yielded very different results. The ferrihydrite SCM favors As(III) over As(V) and has carbonate and silica species as the main competitors for surface sites. In contrast, the goethite SCM has a greater affinity for As(V) over As(III) while PO43- and Fe(II) form the predominant surface species. The SCM for Pleistocene aquifer sediment resembles most the goethite SCM but shows more Si sorption. Compiled As(III) adsorption data for Holocene sediment was also well described by the SCM determined for Pleistocene aquifer sediment, suggesting a comparable As(III) affinity of Holocene and Pleistocene aquifer sediments. A forced gradient field experiment was conducted in a bank aquifer adjacent to a tributary channel to the Red River, and the passage in the aquifer of mixed groundwater containing up to 74% channel water was observed. The concentrations of As (SCM correctly predicts desorption for As(III) but for Si and PO43- it predicts an increased adsorption instead of desorption. The goethite SCM correctly predicts desorption of both As(III) and PO43- but failed in the prediction of Si desorption. These results indicate that the prediction of As mobility, by using SCMs for synthetic Fe-oxides, will be strongly dependent on the model chosen. The SCM based on the Pleistocene aquifer sediment predicts the desorption of As(III), PO43- and Si quite superiorly, as compared to the SCMs for ferrihydrite and goethite, even though Si desorption is still somewhat under-predicted. The observation that a SCM calibrated on a different sediment can predict our field results so well suggests that sediment based SCMs may be a

  13. Stochastic Spectral Analysis for Characterizing Hydraulic Diffusivity in an Alluvial Fan Aquifer with River Stimulus

    Science.gov (United States)

    Wang, Y. L.; Zha, Y.; Yeh, T. C. J.; Wen, J. C.

    2015-12-01

    Estimation of subsurface hydraulic diffusivity was carried out to understand the characteristics of Zhuoshui River alluvial fan, Taiwan. The fan, an important agricultural and industrial region with high water demand, is located at middle Taiwan with an area of 1800 km2. The prior geo-investigations suggest that the main recharge region of the fan is at an apex along the river. The distribution of soil hydraulic diffusivity was estimated by fusing naturally recurring stimulus provided by river and groundwater head. Specifically, the variance and power spectrum provided by temporal and spatial change of groundwater head in response to river stage variations are analyzed to estimate hydraulic diffusivity distribution. It is found that the hydraulic diffusivity of the fan is at the range from 0.08 to 16 m2/s. The average hydraulic diffusivity at the apex, middle, and tail of the fan along the river is about 0.4, 0.6, and 1.0 m2/s, respectively.

  14. Determining treatment requirements for turbid river water to avoid clogging of aquifer storage and recovery wells in siliceous alluvium.

    Science.gov (United States)

    Page, Declan; Vanderzalm, Joanne; Miotliński, Konrad; Barry, Karen; Dillon, Peter; Lawrie, Ken; Brodie, Ross S

    2014-12-01

    The success of Aquifer Storage and Recovery (ASR) schemes relies on defining appropriate design and operational parameters in order to maintain high rates of recharge over the long term. The main contribution of this study was to define the water quality criteria and hence minimum pre-treatment requirements to allow sustained recharge at an acceptable rate in a medium-coarse sand aquifer. The source water was turbid, natural water from the River Darling, Australia. Three treatments were evaluated: bank filtration; coagulation and chlorine disinfection; and coagulation plus granular activated carbon and chlorine disinfection (GAC). Raw source water and the three treated waters were used in laboratory columns packed with aquifer material in replicate experiments in saturated conditions at constant temperature (19 °C) with light excluded for 37 days. Declines in hydraulic conductivity from a mean of 2.17 m/d occurred over the 37 days of the experiment. The GAC-treated water gave an 8% decline in hydraulic conductivity over the 16 cm length of columns, which was significantly different from the other three source waters, which had mean declines of 26-29%. Within the first 3 cm of column length, where most clogging occurred in each column, the mean hydraulic conductivity declined by 10% for GAC-treated water compared with 40-50% for the other source waters. There was very little difference between the columns until day 21, despite high turbidity (78 NTU) in the source water. Reducing turbidity by treatment was not sufficient to offset the reductions in hydraulic conductivity. Biological clogging was found to be most important as revealed by the accumulation of polysaccharides and bacterial numbers in columns when they were dissected and analysed at the end of the experiment. Further chemical clogging through precipitation of minerals was found not to occur within the laboratory columns, and dispersion of clay was also found to be negligible. Due to the low

  15. Groundwater components in the alluvial aquifer of the alpine Rhone River valley, Bois de Finges area, Wallis Canton, Switzerland

    Science.gov (United States)

    Schürch, Marc; Vuataz, François-D.

    2000-09-01

    Source, type, and quantity of various components of groundwater, as well as their spatial and temporal variations were determined by different hydrochemical methods in the alluvial aquifer of the upper Rhone River valley, Bois de Finges, Wallis Canton, Switzerland. The methods used are hydrochemical modeling, stable-isotope analysis, and chemical analysis of surface water and groundwater. Sampling during high- and low-water periods determined the spatial distribution of the water chemistry, whereas monthly sampling over three years provided a basis for understanding seasonal variability. The physico-chemical parameters of the groundwater have spatial and seasonal variations. The groundwater chemical composition of the Rhone alluvial aquifer indicates a mixing of weakly mineralized Rhone River water and SO4-rich water entering from the south side of the valley. Temporal changes in groundwater chemistry and in groundwater levels reflect the seasonal variations of the different contributors to groundwater recharge. The Rhone River recharges the alluvial aquifer only during the summer high-water period. Résumé. Origine, type et quantité de nombreux composants d'eau de l'aquifère alluvial dans la vallée supérieure du Rhône, Bois de Finges, Valais, Suisse, ainsi que leurs variations spatiales et temporelles ont été déterminés par différentes méthodes hydrochimiques. Les méthodes utilisées sont la modélisation hydrochimique, les isotopes stables, ainsi que l'échantillonnage en période de hautes eaux et de basses eaux pour étudier la distribution spatiale de la composition chimique, alors qu'un échantillonnage mensuel pendant trois ans sert à comprendre les processus de la variabilité saisonnière. Les paramètres physico-chimiques des eaux souterraines montrent des variations spatiales et saisonnières. La composition chimique de l'aquifère alluvial du Rhône indique un mélange entre une eau peu minéralisée venant du Rhône et une eau sulfatée s

  16. The ESPAT tool: a general-purpose DSS shell for solving stochastic optimization problems in complex river-aquifer systems

    Science.gov (United States)

    Macian-Sorribes, Hector; Pulido-Velazquez, Manuel; Tilmant, Amaury

    2015-04-01

    Stochastic programming methods are better suited to deal with the inherent uncertainty of inflow time series in water resource management. However, one of the most important hurdles in their use in practical implementations is the lack of generalized Decision Support System (DSS) shells, usually based on a deterministic approach. The purpose of this contribution is to present a general-purpose DSS shell, named Explicit Stochastic Programming Advanced Tool (ESPAT), able to build and solve stochastic programming problems for most water resource systems. It implements a hydro-economic approach, optimizing the total system benefits as the sum of the benefits obtained by each user. It has been coded using GAMS, and implements a Microsoft Excel interface with a GAMS-Excel link that allows the user to introduce the required data and recover the results. Therefore, no GAMS skills are required to run the program. The tool is divided into four modules according to its capabilities: 1) the ESPATR module, which performs stochastic optimization procedures in surface water systems using a Stochastic Dual Dynamic Programming (SDDP) approach; 2) the ESPAT_RA module, which optimizes coupled surface-groundwater systems using a modified SDDP approach; 3) the ESPAT_SDP module, capable of performing stochastic optimization procedures in small-size surface systems using a standard SDP approach; and 4) the ESPAT_DET module, which implements a deterministic programming procedure using non-linear programming, able to solve deterministic optimization problems in complex surface-groundwater river basins. The case study of the Mijares river basin (Spain) is used to illustrate the method. It consists in two reservoirs in series, one aquifer and four agricultural demand sites currently managed using historical (XIV century) rights, which give priority to the most traditional irrigation district over the XX century agricultural developments. Its size makes it possible to use either the SDP or

  17. Baseline mapping study of the Steed Pond aquifer and vadose zone beneath A/M Area, Savannah River Site, Aiken, South Carolina

    International Nuclear Information System (INIS)

    Jackson, D.G. Jr.

    2000-01-01

    This report presents the second phase of a baseline mapping project conducted for the Environmental Restoration Department (ERD) at Savannah River Site. The purpose of this second phase is to map the structure and distribution of mud (clay and silt-sized sediment) within the vadose zone beneath A/M Area. The results presented in this report will assist future characterization and remediation activities in the vadose zone and upper aquifer zones in A/M Area

  18. Multilevel groundwater monitoring of hydraulic head and temperature in the eastern Snake River Plain aquifer, Idaho National Laboratory, Idaho, 2011-13

    Science.gov (United States)

    Twining, Brian V.; Fisher, Jason C.

    2015-01-01

    From 2011 to 2013, the U.S. Geological Survey’s Idaho National Laboratory (INL) Project Office, in cooperation with the U.S. Department of Energy, collected depth-discrete measurements of fluid pressure and temperature in 11 boreholes located in the eastern Snake River Plain aquifer. Each borehole was instrumented with a multilevel monitoring system (MLMS) consisting of a series of valved measurement ports, packer bladders, casing segments, and couplers.

  19. A Trans-disciplinary Hydrogeological Systems Analysis Approach for Identifying and Assessing Managed Aquifer Recharge Options: Example from the Darling River Floodplain, N.S.W., Australia

    Science.gov (United States)

    Lawrie, K.; Brodie, R. S.; Tan, K. P.; Halas, L.; Magee, J.; Gow, L.; Christensen, N. B.

    2013-12-01

    Surface water availability and quality generally limits managed aquifer recharge (MAR) opportunities in inland Australia's highly salinized landscapes and groundwater systems. Economic factors also commonly limit MAR investigations to shallow freshwater groundwater systems near existing infrastructure. Aquifer opportunities lie mainly in zones of fresh groundwater in relatively thin fluvial sedimentary aquifer systems with highly variable hydraulic properties. As part of a broader strategy to identify water savings in the Murray-Darling Basin, the Broken Hill Managed Aquifer Recharge (BHMAR) project was tasked with identifying and assessing MAR and/or groundwater extraction options to reduce evaporative losses from existing surface water storages, secure Broken Hill's water supply, protect the local environment and heritage, and return water to the river system. A trans-disciplinary research approach was used to identify and assess MAR options across a broad area of the Darling River floodplain. This methodology enabled the team to recognise fundamental problems in discipline approaches, helped identify critical data gaps, led to significant innovation across discipline boundaries, was critical in the development of a new hydrogeological conceptual model, facilitated development of new models of landscape, geological and tectonic evolution of the study area, and enabled completion of pre-commissioning maximal and residual MAR risk assessments. An airborne electromagnetics (AEM) survey, acquired over a large (>7,500 sq km) area of the Darling Floodplain, enabled rapid identification of a multi-layer sequence of aquifers and aquitards, while a phased assessment methodology was developed to rapidly identify and assess over 30 potential MAR targets (largely in fresh groundwater zones within palaeochannels and at palaeochannel confluences). Hydraulic properties were confirmed by a 7.5 km drilling program (100 sonic and rotary mud holes), and complementary field

  20. Persistence of uranium groundwater plumes: Contrasting mechanisms at two DOE sites in the groundwater-river interaction zone

    Science.gov (United States)

    Zachara, John M.; Long, Philip E.; Bargar, John; Davis, James A.; Fox, Patricia; Fredrickson, Jim K.; Freshley, Mark D.; Konopka, Allan E.; Liu, Chongxuan; McKinley, James P.; Rockhold, Mark L.; Williams, Kenneth H.; Yabusaki, Steve B.

    2013-04-01

    We examine subsurface uranium (U) plumes at two U.S. Department of Energy sites that are located near large river systems and are influenced by groundwater-river hydrologic interaction. Following surface excavation of contaminated materials, both sites were projected to naturally flush remnant uranium contamination to levels below regulatory limits (e.g., 30 μg/L or 0.126 μmol/L; U.S. EPA drinking water standard), with 10 years projected for the Hanford 300 Area (Columbia River) and 12 years for the Rifle site (Colorado River). The rate of observed uranium decrease was much lower than expected at both sites. While uncertainty remains, a comparison of current understanding suggests that the two sites have common, but also different mechanisms controlling plume persistence. At the Hanford 300 A, the persistent source is adsorbed U(VI) in the vadose zone that is released to the aquifer during spring water table excursions. The release of U(VI) from the vadose zone and its transport within the oxic, coarse-textured aquifer sediments is dominated by kinetically-limited surface complexation. Modeling implies that annual plume discharge volumes to the Columbia River are small (oxidation of naturally reduced, contaminant U(IV) in the saturated zone and a continuous influx of U(VI) from natural, up-gradient sources influence plume persistence. Rate-limited mass transfer and surface complexation also control U(VI) migration velocity in the sub-oxic Rifle groundwater. Flux of U(VI) from the vadose zone at the Rifle site may be locally important, but it is not the dominant process that sustains the plume. A wide range in microbiologic functional diversity exists at both sites. Strains of Geobacter and other metal reducing bacteria are present at low natural abundance that are capable of enzymatic U(VI) reduction in localized zones of accumulated detrital organic carbon or after organic carbon amendment. Major differences between the sites include the geochemical nature of

  1. Persistence of uranium groundwater plumes: contrasting mechanisms at two DOE sites in the groundwater-river interaction zone.

    Science.gov (United States)

    Zachara, John M; Long, Philip E; Bargar, John; Davis, James A; Fox, Patricia; Fredrickson, Jim K; Freshley, Mark D; Konopka, Allan E; Liu, Chongxuan; McKinley, James P; Rockhold, Mark L; Williams, Kenneth H; Yabusaki, Steve B

    2013-04-01

    We examine subsurface uranium (U) plumes at two U.S. Department of Energy sites that are located near large river systems and are influenced by groundwater-river hydrologic interaction. Following surface excavation of contaminated materials, both sites were projected to naturally flush remnant uranium contamination to levels below regulatory limits (e.g., 30 μg/L or 0.126 μmol/L; U.S. EPA drinking water standard), with 10 years projected for the Hanford 300 Area (Columbia River) and 12 years for the Rifle site (Colorado River). The rate of observed uranium decrease was much lower than expected at both sites. While uncertainty remains, a comparison of current understanding suggests that the two sites have common, but also different mechanisms controlling plume persistence. At the Hanford 300 A, the persistent source is adsorbed U(VI) in the vadose zone that is released to the aquifer during spring water table excursions. The release of U(VI) from the vadose zone and its transport within the oxic, coarse-textured aquifer sediments is dominated by kinetically-limited surface complexation. Modeling implies that annual plume discharge volumes to the Columbia River are small (oxidation of naturally reduced, contaminant U(IV) in the saturated zone and a continuous influx of U(VI) from natural, up-gradient sources influence plume persistence. Rate-limited mass transfer and surface complexation also control U(VI) migration velocity in the sub-oxic Rifle groundwater. Flux of U(VI) from the vadose zone at the Rifle site may be locally important, but it is not the dominant process that sustains the plume. A wide range in microbiologic functional diversity exists at both sites. Strains of Geobacter and other metal reducing bacteria are present at low natural abundance that are capable of enzymatic U(VI) reduction in localized zones of accumulated detrital organic carbon or after organic carbon amendment. Major differences between the sites include the geochemical nature of

  2. Numerical simulation of groundwater and surface-water interactions in the Big River Management Area, central Rhode Island

    Science.gov (United States)

    Masterson, John P.; Granato, Gregory E.

    2013-01-01

    The Rhode Island Water Resources Board is considering use of groundwater resources from the Big River Management Area in central Rhode Island because increasing water demands in Rhode Island may exceed the capacity of current sources. Previous water-resources investigations in this glacially derived, valley-fill aquifer system have focused primarily on the effects of potential groundwater-pumping scenarios on streamflow depletion; however, the effects of groundwater withdrawals on wetlands have not been assessed, and such assessments are a requirement of the State’s permitting process to develop a water supply in this area. A need for an assessment of the potential effects of pumping on wetlands in the Big River Management Area led to a cooperative agreement in 2008 between the Rhode Island Water Resources Board, the U.S. Geological Survey, and the University of Rhode Island. This partnership was formed with the goal of developing methods for characterizing wetland vegetation, soil type, and hydrologic conditions, and monitoring and modeling water levels for pre- and post-water-supply development to assess potential effects of groundwater withdrawals on wetlands. This report describes the hydrogeology of the area and the numerical simulations that were used to analyze the interaction between groundwater and surface water in response to simulated groundwater withdrawals. The results of this analysis suggest that, given the hydrogeologic conditions in the Big River Management Area, a standard 5-day aquifer test may not be sufficient to determine the effects of pumping on water levels in nearby wetlands. Model simulations showed water levels beneath Reynolds Swamp declined by about 0.1 foot after 5 days of continuous pumping, but continued to decline by an additional 4 to 6 feet as pumping times were increased from a 5-day simulation period to a simulation period representative of long-term average monthly conditions. This continued decline in water levels with

  3. Using radon-222 to study coastal groundwater/surface-water interaction in the Crau coastal aquifer (southeastern France)

    Science.gov (United States)

    Mayer, Adriano; Nguyen, Bach Thao; Banton, Olivier

    2016-11-01

    Radon has been used to determine groundwater velocity and groundwater discharge into wetlands at the southern downstream boundary of the Crau aquifer, southeastern France. This aquifer constitutes an important high-quality freshwater resource exploited for agriculture, industry and human consumption. An increase in salinity occurs close to the sea, highlighting the need to investigate the water balance and groundwater behavior. Darcy velocity was estimated using radon activities in well waters according to the Hamada "single-well method" (involving comparison with radon in groundwater in the aquifer itself). Measurements done at three depths (7, 15 and 21 m) provided velocity ranging from a few mm/day to more than 20 cm/day, with highest velocities observed at the 15-m depth. Resulting hydraulic conductivities agree with the known geology. Waters showing high radon activity and high salinity were found near the presumed shoreline at 3,000 years BP, highlighting the presence of ancient saltwater. Radon activity has also been measured in canals, rivers and ponds, to trace groundwater discharges and evaluate water balance. A model of the radon spatial evolution explains the observed radon activities. Groundwater discharge to surface water is low in pond waters (4 % of total inputs) but significant in canals (55 l/m2/day).

  4. A comparative evaluation of conceptual models for the Snake River Plain aquifer at the Idaho Chemical Processing Plant, INEL

    International Nuclear Information System (INIS)

    Prahl, C.J.

    1992-01-01

    Geologic and hydrologic data collected by the United States Geological Survey (USGS) are used to evaluate the existing ground water monitoring well network completed in the upper portion of the Snake River Plain aquifer (SRPA) beneath the Idaho Chemical Processing Plant (ICPP). The USGS data analyzed and compared in this study include: (a) lithologic, geophysical, and stratigraphic information, including the conceptual geologic models intrawell, ground water flow measurement (Tracejector tests) and (c) dedicated, submersible, sampling group elevations. Qualitative evaluation of these data indicate that the upper portion of the SRPA is both heterogeneous and anisotropic at the scale of the ICPP monitoring well network. Tracejector test results indicate that the hydraulic interconnection and spatial configuration of water-producing zones is extremely complex within the upper portion of the SRPA. The majority of ICPP monitoring wells currently are equipped to sample ground water only the upper lithostratigraphic intervals of the SRPA, primarily basalt flow groups E, EF, and F. Depth-specific hydrogeochemical sampling and analysis are necessary to determine if ground water quality varies significantly between the various lithostratigraphic units adjacent to individual sampling pumps

  5. Hydrogeology and simulation of groundwater flow and analysis of projected water use for the Canadian River alluvial aquifer, western and central Oklahoma

    Science.gov (United States)

    Ellis, John H.; Mashburn, Shana L.; Graves, Grant M.; Peterson, Steven M.; Smith, S. Jerrod; Fuhrig, Leland T.; Wagner, Derrick L.; Sanford, Jon E.

    2017-02-13

    This report describes a study of the hydrogeology and simulation of groundwater flow for the Canadian River alluvial aquifer in western and central Oklahoma conducted by the U.S. Geological Survey in cooperation with the Oklahoma Water Resources Board. The report (1) quantifies the groundwater resources of the Canadian River alluvial aquifer by developing a conceptual model, (2) summarizes the general water quality of the Canadian River alluvial aquifer groundwater by using data collected during August and September 2013, (3) evaluates the effects of estimated equal proportionate share (EPS) on aquifer storage and streamflow for time periods of 20, 40, and 50 years into the future by using numerical groundwater-flow models, and (4) evaluates the effects of present-day groundwater pumping over a 50-year period and sustained hypothetical drought conditions over a 10-year period on stream base flow and groundwater in storage by using numerical flow models. The Canadian River alluvial aquifer is a Quaternary-age alluvial and terrace unit consisting of beds of clay, silt, sand, and fine gravel sediments unconformably overlying Tertiary-, Permian-, and Pennsylvanian-age sedimentary rocks. For groundwater-flow modeling purposes, the Canadian River was divided into Reach I, extending from the Texas border to the Canadian River at the Bridgeport, Okla., streamgage (07228500), and Reach II, extending downstream from the Canadian River at the Bridgeport, Okla., streamgage (07228500), to the confluence of the river with Eufaula Lake. The Canadian River alluvial aquifer spans multiple climate divisions, ranging from semiarid in the west to humid subtropical in the east. The average annual precipitation in the study area from 1896 to 2014 was 34.4 inches per year (in/yr).A hydrogeologic framework of the Canadian River alluvial aquifer was developed that includes the areal and vertical extent of the aquifer and the distribution, texture variability, and hydraulic properties of

  6. Groundwater and surface-water interaction within the upper Smith River Watershed, Montana 2006-2010

    Science.gov (United States)

    Caldwell, Rodney R.; Eddy-Miller, Cheryl A.

    2013-01-01

    and surface-water interactions occur downstream from the confluence of the North and South Fork Smith Rivers, but are less discernible compared to the overall magnitude of the main-stem streamflow. The Smith River was perennial throughout the study. Monitoring sites along the Smith River generally displayed small head gradients between the stream and the groundwater, while one site consistently showed strongly gaining conditions. Synoptic streamflow measurements during periods of limited irrigation diversion in 2007 and 2008 consistently showed gains over the upper 41.4 river miles of the main stem Smith River where net gains ranged from 13.0 to 28.9 cubic feet per second. Continuous streamflow data indicated net groundwater discharge and small-scale tributary inflow contributions of around 25 cubic feet per second along the upper 10-mile reach of the Smith River for most of the 2010 record. A period of intense irrigation withdrawal during the last two weeks in May was followed by a period (early June 2010 to mid-July 2010) with the largest net increase (an average of 71.1 cubic feet per second) in streamflow along this reach of the Smith River. This observation is likely due to increased groundwater discharge to the Smith River resulting from irrigation return flow. By late July, the apparent effects of return flows receded, and the net increase in streamflow returned to about 25 cubic feet per second. Two-dimensional heat and solute transport VS2DH models representing selected stream cross sections were used to constrain the hydraulic properties of the Quaternary alluvium and estimate temporal water-flux values through model boundaries. Hydraulic conductivity of the Quaternary alluvium of the modeled sections ranged from 3x10-6 to 4x10-5 feet per second. The models showed reasonable approximations of the streambed and shallow aquifer environment, and the dynamic changes in water flux between the stream and the groundwater through different model boundaries.

  7. Interaction between opposite river bank dynamics

    NARCIS (Netherlands)

    Bonilla Porras, J.A.; Crosato, A.; Uijttewaal, W.S.J.

    2017-01-01

    Although many studies regarding bank erosion  and accretion can be found in the literature, it is  not common to find works studying the interaction  between opposite banks. Some existing  morphodynamic models describe bank erosion as  an event that depends on

  8. Surface complexation modeling for predicting solid phase arsenic concentrations in the sediments of the Mississippi River Valley alluvial aquifer, Arkansas, USA

    Science.gov (United States)

    Sharif, M.S.U.; Davis, R.K.; Steele, K.F.; Kim, B.; Hays, P.D.; Kresse, T.M.; Fazio, J.A.

    2011-01-01

    The potential health impact of As in drinking water supply systems in the Mississippi River Valley alluvial aquifer in the state of Arkansas, USA is significant. In this context it is important to understand the occurrence, distribution and mobilization of As in the Mississippi River Valley alluvial aquifer. Application of surface complexation models (SCMs) to predict the sorption behavior of As and hydrous Fe oxides (HFO) in the laboratory has increased in the last decade. However, the application of SCMs to predict the sorption of As in natural sediments has not often been reported, and such applications are greatly constrained by the lack of site-specific model parameters. Attempts have been made to use SCMs considering a component additivity (CA) approach which accounts for relative abundances of pure phases in natural sediments, followed by the addition of SCM parameters individually for each phase. Although few reliable and internally consistent sorption databases related to HFO exist, the use of SCMs using laboratory-derived sorption databases to predict the mobility of As in natural sediments has increased. This study is an attempt to evaluate the ability of the SCMs using the geochemical code PHREEQC to predict solid phase As in the sediments of the Mississippi River Valley alluvial aquifer in Arkansas. The SCM option of the double-layer model (DLM) was simulated using ferrihydrite and goethite as sorbents quantified from chemical extractions, calculated surface-site densities, published surface properties, and published laboratory-derived sorption constants for the sorbents. The model results are satisfactory for shallow wells (10.6. m below ground surface), where the redox condition is relatively oxic or mildly suboxic. However, for the deep alluvial aquifer (21-36.6. m below ground surface) where the redox condition is suboxic to anoxic, the model results are unsatisfactory. ?? 2011 Elsevier Ltd.

  9. Substrate interactions of benzene, toluene, and para-xylene during microbial degradation by pure cultures and mixed culture aquifer slurries

    International Nuclear Information System (INIS)

    Alvarez, P.J.J.; Vogel, T.M.

    1991-01-01

    Release of petroleum hydrocarbons in the environment is a widespread occurrence. One particular concern is the contamination of drinking water sources by the toxic, water-soluble, and mobile petroleum components benzene, toluene, and xylene (BTX). Benzene, toluene, and p-xylene (BTX) were degraded by indigenous mixed cultures in sandy aquifer material and by two pure cultures isolated from the same site. Although BTX compounds have a similar chemical structure, the fate of individual BTX compounds differed when the compounds were fed to each pure culture and mixed culture aquifer slurries. The identification of substrate interactions aided the understanding of this behavior. Beneficial substrate interactions included enhanced degradation of benzene-dependent degradation of toluene and p-xylene by Arthrobacter sp. strain HCB. Detrimental substrate interactions included retardation in benzene and toluene degradation by the presence of p-xylene in both aquifer slurries and Pseudomonas incubations. The catabolic diversity of microbes in the environment precludes generalizations about the capacity of individual BTX compounds to enhance or inhibit the degradation of other BTX compounds

  10. Arsenic mobilization and attenuation by mineral–water interactions: implications for managed aquifer recharge

    Science.gov (United States)

    Managed aquifer recharge (MAR) has a potential for addressing deficits in water supplies worldwide. It is also widely used for preventing saltwater intrusion, maintaining the groundwater table, and augmenting ecological stream flows among many beneficial environmental application...

  11. Deposition, persistence and turnover of pollutants: first results from the EU project AquaTerra for selected river basins and aquifers

    DEFF Research Database (Denmark)

    Barth, J.A.C.; Steidle, D.; Kuntz, D.

    2007-01-01

    in laboratory studies with soils and aquifer material from selected sites. For sediment transport of contaminants, new flood sampling techniques revealed highest deposition rates of beta-hexachlorocyclohexane (beta-HCH) in river sediments at hotspot areas on the Mulde River in the Bitterfeld region (Elbe Basin...... that range from biogeochemistry, environmental engineering, computer modelling and chemistry to socio-economic sciences. Field study areas are the river basins of the Ebro, the Meuse, the Elbe and the Danube as well as the 3-km(2) French catchment of the Brevilles Spring. Within the first 2 years...... of the project more than 1700 samples of atmospherically deposited particles, sediments, and water have been collected in the above-mentioned systems. Results show clear spatial patterns of deposition of polyaromatic hydrocarbons (PAHs) with the highest rates in the Meuse Basin. For local inputs...

  12. Hydrologic influences on water-level changes in the Eastern Snake River Plain aquifer at and near the Idaho National Laboratory, Idaho, 1949-2014

    Science.gov (United States)

    Bartholomay, Roy C.; Twining, Brian V.

    2015-01-01

    The U.S. Geological Survey, in cooperation with the U.S. Department of Energy, has maintained a water-level monitoring program at the Idaho National Laboratory (INL) since 1949 to systematically measure water levels to provide long-term information on groundwater recharge, discharge, movement, and storage in the eastern Snake River Plain (ESRP) aquifer. During 2014, water levels in the ESRP aquifer reached all-time lows for the period of record, prompting this study to assess the effect that future water-level declines may have on pumps and wells. Water-level data were compared with pump-setting depth to determine the hydraulic head above the current pump setting. Additionally, geophysical logs were examined to address changes in well productivity with water-level declines. Furthermore, hydrologic factors that affect water levels in different areas of the INL were evaluated to help understand why water-level changes occur.

  13. Preliminary Analysis of the Role of Wetlands and Rivers in the Groundwater Discharge of the Guarani Aquifer System in NE Argentina

    Energy Technology Data Exchange (ETDEWEB)

    Vives, L., E-mail: lvives@faa.unicen.edu.ar [Instituto de Hidrologia de Llanuras, Universidad Nacional del Centro de la Provincia de Buenos Aires, Azul (Argentina); Rodriguez, L. [Centro de Estudios Hidroambientales, Facultad de Ingenieria y Ciencias Hidricas, Universidad Nacional del Litoral, Santa Fe (Argentina); Manzano, M. [Escuela de Ingenieria de Caminos y de Minas, Universidad Politecnica de Cartagena, Cartagena (Spain); Valladares, A. [Subsecretaria de Recursos Hidricos (Argentina); Aggarwal, P. K.; Araguas Araguas, L. [International Atomic Energy Angency, Vienna (Austria)

    2013-07-15

    The Guarani Aquifer System (GAS) is the largest aquifer in South America. Previous regional hydrochemical and isotopic studies suggested that discharge may occur at wetlands and reaches of the Parana and Uruguay Rivers. Preliminary findings of a project aimed at verifying the discharge hypothesis on the southern GAS region are presented. The hydrochemical- isotopic composition of 17 samples from surface and groundwater in that area were analysed. Some waters showed chemical facies and isotopic (stable isotope and carbon-14) signatures similar to the formerly identified as GAS+pre-GAS formations. Admixtures between modern and GAS+pre-GAS waters were found at depths between less than 100 m and 200 m. A 96 m deep well located near the Ibera lagoon showed chemical and isotopic composition indicating presence of GAS waters. The hydraulic gradient favours upward flow near the wetlands, but surface waters seem to originate from local recharge. Investigations continue, incorporating {sup 222}Rn and new sampling sites. (author)

  14. Rainfall-runoff modelling and palaeoflood hydrology applied to reconstruct centennial scale records of flooding and aquifer recharge in ungauged ephemeral rivers

    Directory of Open Access Journals (Sweden)

    G. Benito

    2011-04-01

    Full Text Available In this study we propose a multi-source data approach for quantifying long-term flooding and aquifer recharge in ungauged ephemeral rivers. The methodology is applied to the Buffels River, at 9000 km2 the largest ephemeral river in Namaqualand (NW South Africa, a region with scarce stream flow records limiting research investigating hydrological response to global change. Daily discharge and annual flood series (1965–2006 were estimated from a distributed rainfall-runoff hydrological model (TETIS using rainfall gauge records located within the catchment. The model was calibrated and validated with data collected during a two year monitoring programme (2005–2006 at two stream flow stations, one each in the upper and lower reaches of the catchment. In addition to the modelled flow records, non-systematic flood data were reconstructed using both sedimentary and documentary evidence. The palaeoflood record identified at least 25 large floods during the last 700 yr; with the largest floods reaching a minimum discharge of 255 m3 s−1 (450 yr return period in the upper basin, and 510 m3 s−1 (100 yr return period in the lower catchment. Since AD 1925, the flood hydrology of the Buffels River has been characterised by a decrease in the magnitude and frequency of extreme floods, with palaeoflood discharges (period 1500–1921 five times greater than the largest modelled floods during the period 1965–2006. Large floods generated the highest hydrograph volumes, however their contribution to aquifer recharge is limited as this depends on other factors such as flood duration and storage capacity of the unsaturated zone prior to the flood. Floods having average return intervals of 5–10 yr (120–140 m3 s−1 and flowing for 12 days are able to fully saturate the Spektakel aquifer in the lower Buffels River basin. Alluvial aquifer storage capacity limiting potential recharge

  15. A European initiative to define research needs and foster the adoption of Managed Aquifer Recharge into river basin management

    Science.gov (United States)

    Kneppers, Angeline; Grützmacher, Gesche; Kazner, Christian; Zojer, Hans

    2010-05-01

    The European Technology Platform for Water (WssTP) was initiated by the European Commission to federate a highly fragmented sector with the aim to foster competitive innovations and promote sustainable solutions. To achieve this, pilot programmes endorsing a bottom-up approach were launched in 2007 with a variety of stakeholders having representative water issues to solve. Integrated Water Resources Management (IWRM) was adopted as a balancing process for the safe and sustainable development, allocation and monitoring of water resource use in the context of current and future social, economic and environmental objectives. As a result key drivers were selected and a methodology was followed to identify and validate the needs with stakeholders and experts, and demonstrate solutions as an integrated part of the river basin management plans. Managed Aquifer Recharge (MAR) was identified as a key component of integrated water resources management, especially in water scarce regions and an area relevant for further research. The paper shall summarize the process followed by the WssTP, initiating a Task Force with 36 representatives from European research institutes and industry partners with participation of a few international experts. During a workshop conducted in Graz in June 2009 these experts developed the basis for a report that has now been submitted to the European Commission for consideration in future research calls. Implementing IWRM and MAR is made difficult by the number of different water bodies, but also by the large number of stakeholders, policies, legislations and conflicting interests. The results of the MAR Task Force initiative set the basis for further discussions with the international MAR community on the relevance of the identified research needs but also on the importance and process to associate the institutional and managerial entities for capacity building and the adoption of MAR into the overall management strategies.

  16. Estimates of ground-water pumpage from the Yakima River Basin aquifer system, Washington, 1960-2000

    Science.gov (United States)

    Vaccaro, J.J.; Sumioka, S.S.

    2006-01-01

    and August and during 2000, was about 100 cubic feet per second each month averaged over the Yakima River Basin aquifer system. During 2000, non-standby/reserve pumpage associated with ground-water rights was estimated to total 253,454 acre-feet, or about 198,290 acre-feet less than the appropriated quantity. The unused part of the appropriated value is about equivalent to the irrigation pumpage for primary rights.

  17. Groundwater-Surface Water Interactions and Downstream Transport of Water, Heat, and Solutes in a Hydropeaked River

    Science.gov (United States)

    Ferencz, S. B.; Cardenas, M. B.; Neilson, B. T.; Watson, J.

    2017-12-01

    A majority of the world's largest river systems are regulated by dams. In addition to being used for water resources management and flood prevention, many large dams are also used for hydroelectric power generation. In the United States, dams account for 7% of domestic electricity, and hydropower accounts for 16% of worldwide electricity production. To help meet electricity demand during peak usage times, hydropower utilities often increase their releases of water during high demand periods. This practice, termed hydropeaking, can cause large transient flow regimes downstream of hydroelectric dams. These transient flow increases can result in order of magnitude daily fluctuations in discharge, and the released water can have different thermal and chemical properties than ambient river water. As hydropeaking releases travel downstream, the temporary rise in stage and increase in discharge can enhance surface water-groundwater (SW-GW) exchange between the river and its alluvial aquifer. This dam-induced SW-GW exchange, combined with hydrodynamic attenuation and heat exchange processes, result in complex responses downstream. The dam-regulated Lower Colorado River downstream of Austin, TX was used as a natural laboratory to observe SW-GW interactions and downstream transport of water, heat, and solutes under hydropeaking conditions. To characterize SW-GW interactions, well transects were installed in the banks of the river to observe exchanges between the river and alluvial aquifer. The well transects were installed at three different distances from the dam (15km, 35km, and 80km). At each well transect conductivity, temperature, and pressure sensors were deployed in the monitoring wells and in the channel. Additional conductivity and temperature sensors were deployed along the study reach to provide a more detailed record of heat and solute transport during hydropeaking releases. The field data spans over two months of daily dam releases that were punctuated by two

  18. Development of a stream-aquifer numerical flow model to assess river water management under water scarcity in a Mediterranean basin.

    Science.gov (United States)

    Mas-Pla, Josep; Font, Eva; Astui, Oihane; Menció, Anna; Rodríguez-Florit, Agustí; Folch, Albert; Brusi, David; Pérez-Paricio, Alfredo

    2012-12-01

    Stream flow, as a part of a basin hydrological cycle, will be sensible to water scarcity as a result of climate change. Stream vulnerability should then be evaluated as a key component of the basin water budget. Numerical flow modeling has been applied to an alluvial formation in a small mountain basin to evaluate the stream-aquifer relationship under these future scenarios. The Arbúcies River basin (116 km(2)) is located in the Catalan Inner Basins (NE Spain) and its lower reach, which is related to an alluvial aquifer, usually becomes dry during the summer period. This study seeks to determine the origin of such discharge losses whether from natural stream leakage and/or induced capture due to groundwater withdrawal. Our goal is also investigating how discharge variations from the basin headwaters, representing potential effects of climate change, may affect stream flow, aquifer recharge, and finally environmental preservation and human supply. A numerical flow model of the alluvial aquifer, based on MODFLOW and especially in the STREAM routine, reproduced the flow system after the usual calibration. Results indicate that, in the average, stream flow provides more than 50% of the water inputs to the alluvial aquifer, being responsible for the amount of stored water resources and for satisfying groundwater exploitation for human needs. Detailed simulations using daily time-steps permit setting threshold values for the stream flow entering at the beginning of the studied area so surface discharge is maintained along the whole watercourse and ecological flow requirements are satisfied as well. The effects of predicted rainfall and temperature variations on the Arbúcies River alluvial aquifer water balance are also discussed from the outcomes of the simulations. Finally, model results indicate the relevance of headwater discharge management under future climate scenarios to preserve downstream hydrological processes. They also point out that small mountain basins

  19. Yakima River species interactions studies annual report, 2000; ANNUAL

    International Nuclear Information System (INIS)

    Pearsons, Todd N.

    2001-01-01

    Species interactions research and monitoring was initiated in 1989 to investigate ecological interactions among fish in response to proposed supplementation of salmon and steelhead in the upper Yakima River basin. This is the ninth of a series of progress reports that address species interactions research and supplementation monitoring of fishes in the Yakima River basin. Data have been collected prior to supplementation to characterize the ecology and demographics of non-target taxa (NTT) and target taxon, and develop methods to monitor interactions and supplementation success. Major topics of this report are associated with the chronology of ecological interactions that occur throughout a supplementation program, implementing NTT monitoring prescriptions for detecting potential impacts of hatchery supplementation, hatchery fish interactions, and monitoring fish predation indices. This report is organized into four chapters, with a general introduction preceding the first chapter. This annual report summarizes data collected primarily by the Washington Department of Fish and Wildlife (WDFW) between January 1, 2000 and December 31, 2000 in the Yakima basin, however these data were compared to data from previous years to identify preliminary trends and patterns. Summaries of each of the chapters included in this report are described

  20. Evaluation of groundwater levels in the South Platte River alluvial aquifer, Colorado, 1953-2012, and design of initial well networks for monitoring groundwater levels

    Science.gov (United States)

    Wellman, Tristan

    2015-01-01

    The South Platte River and underlying alluvial aquifer form an important hydrologic resource in northeastern Colorado that provides water to population centers along the Front Range and to agricultural communities across the rural plains. Water is regulated based on seniority of water rights and delivered using a network of administration structures that includes ditches, reservoirs, wells, impacted river sections, and engineered recharge areas. A recent addendum to Colorado water law enacted during 2002-2003 curtailed pumping from thousands of wells that lacked authorized augmentation plans. The restrictions in pumping were hypothesized to increase water storage in the aquifer, causing groundwater to rise near the land surface at some locations. The U.S. Geological Survey (USGS), in cooperation with the Colorado Water Conservation Board and the Colorado Water Institute, completed an assessment of 60 years (yr) of historical groundwater-level records collected from 1953 to 2012 from 1,669 wells. Relations of "high" groundwater levels, defined as depth to water from 0 to 10 feet (ft) below land surface, were compared to precipitation, river discharge, and 36 geographic and administrative attributes to identify natural and human controls in areas with shallow groundwater.

  1. Interaction between rivers and bridges in Tuscany (Italy)

    Science.gov (United States)

    Tartaglia, V.; Caporali, E.

    2003-04-01

    The natural adjustment phenomena of the rivers next to the crossing infrastructures, often due to the interaction with the structures themselves, cause damage risk conditions for a high number of structures. About 30 railway bridge sites in Tuscany, interested in the last 30 years by river bed instability, have been monitored. A standardized Bridge Site Inspection Form have been defined and used for the inspections to ensure data reliability and a computer-aided system for data collection have been developed. The system is composed by two components: (1) a GIS that contain the hydrological and geomorphological data layers; (2) a DBMS on which the geomorphological characteristics of the sites and the geometrical and structural characteristics of the bridges are stored with a relational structure. The observed damage mechanisms suggest to schematise the bridge-river interaction as the sum of two instability processes: (a) the lateral instability, when long term evolution of the stream or localized collapse phenomena of the banks can undermine the lateral bridge structures not meant to be exposed to flow (piers whit shallow foundation in the floodplain, long abutments, etc.); (b) vertical instability processes, when the river bed level degradation given by the sum of geomorphological phenomena at the basin scale (general scour) and at the site scale (contraction scour and local scour) can undermine the bridge foundations. To express synthetically the damage risk of bridges, due to instability phenomena of their crossed rivers, the use of a Risk Index is here proposed. The RI is calculated with a semi-qualitative method derived from the geomorphological observations and from the calculated values of some hydraulic variables, obtained by the regional frequency analysis of flood in Tuscany. The RI allows, even in lack of foundation depth data, to individuate the critical sites and to rank them for protection planning. Besides a threshold value of the Risk Index has been

  2. Surface-ground water interactions and hydrogeochemical evolution in a fluvio-deltaic setting: The case study of the Pinios River delta

    Science.gov (United States)

    Matiatos, Ioannis; Paraskevopoulou, Vasiliki; Lazogiannis, Konstantinos; Botsou, Fotini; Dassenakis, Manos; Ghionis, George; Alexopoulos, John D.; Poulos, Serafim E.

    2018-06-01

    River deltas sustain important ecosystems with rich biodiversity and large biomass, as well as human populations via the availability of water and food sources. Anthropogenic activities, such as urbanization, tourism and agriculture, may pose threats to river deltas. The knowledge of the factors controlling the regional water quality regime in these areas is important for planning sustainable use and management of the water resources. Here, hydrochemical methods and multivariate statistical techniques were combined to investigate the shallow aquifer of the Pinios River (Thessaly) deltaic plain with respect to water quality, hydrogeochemical evolution and interactions between groundwater and surface water bodies. Water quality assessment indicated that most of the river and groundwater samples fully comply with the criteria set by the Drinking Water Directive (98/83/EC). The river is recharged mainly from springs of the Tempi valley and the shallow aquifer, and to a lesser degree from precipitation, throughout the year. The hydrogeochemical characteristics indicated a cation (Ca, Mg, and Na) bicarbonate water type, which evolves to calcium-chloride, sodium-bicarbonate and sodium-chloride water type, in the northern part of the delta. Calcite and dolomite dissolution determined the major ion chemistry, but other processes, such as silicate weathering and cation exchange reactions, also contributed. In the northern part of the plain, the interaction with the deeper aquifer enriched the shallow aquifer with Na and Cl ions. Principal Component Analysis showed that five components (PCs) explain 77% of the total variance of water quality parameters; these are: (1) salinity; (2) water-silicate rocks interaction; (3) hardness due to calcite dissolution, and cation exchange processes; (4) nitrogen pollution; and (5) non-N-related artificial fertilizers. This study demonstrated that the variation of water hydrochemistry in the deltaic plain could be attributed to natural and

  3. Multi-tracer investigation of river and groundwater interactions: a case study in Nalenggele River basin, northwest China

    Science.gov (United States)

    Xu, Wei; Su, Xiaosi; Dai, Zhenxue; Yang, Fengtian; Zhu, Pucheng; Huang, Yong

    2017-11-01

    Environmental tracers (such as major ions, stable and radiogenic isotopes, and heat) monitored in natural waters provide valuable information for understanding the processes of river-groundwater interactions in arid areas. An integrated framework is presented for interpreting multi-tracer data (major ions, stable isotopes (2H, 18O), the radioactive isotope 222Rn, and heat) for delineating the river-groundwater interactions in Nalenggele River basin, northwest China. Qualitative and quantitative analyses were undertaken to estimate the bidirectional water exchange associated with small-scale interactions between groundwater and surface water. Along the river stretch, groundwater and river water exchange readily. From the high mountain zone to the alluvial fan, groundwater discharge to the river is detected by tracer methods and end-member mixing models, but the river has also been identified as a losing river using discharge measurements, i.e. discharge is bidirectional. On the delta-front of the alluvial fan and in the alluvial plain, in the downstream area, the characteristics of total dissolved solids values, 222Rn concentrations and δ18O values in the surface water, and patterns derived from a heat-tracing method, indicate that groundwater discharges into the river. With the environmental tracers, the processes of river-groundwater interaction have been identified in detail for better understanding of overall hydrogeological processes and of the impacts on water allocation policies.

  4. Predictive models applied to groundwater level forecasting: a preliminary experience on the alluvial aquifer of the Magra River (Italy).

    Science.gov (United States)

    Brozzo, Gianpiero; Doveri, Marco; Lelli, Matteo; Scozzari, Andrea

    2010-05-01

    Computer-based decision support systems are getting a growing interest for water managing authorities and water distribution companies. This work discusses a preliminary experience in the application of computational intelligence in a hydrological modeling framework, regarding the study area of the alluvial aquifer of the Magra River (Italy). Two sites in the studied area, corresponding to two distinct groups of wells (Battifollo and Fornola) are managed by the local drinkable water distribution company (ACAM Acque), which serves the area of La Spezia, on the Ligurian coast. Battifollo has 9 wells with a total extraction rate of about 240 liters per second, while Fornola has 44 wells with an extraction rate of about 900 liters per second. Objective of this work is to make use of time series coming from long-term monitoring activities in order to assess the trend of the groundwater level with respect to a set of environmental and exploitation parameters; this is accomplished by the experimentation of a suitable model, eligible to be used as a predictor. This activity moves on from the modeling of the system behavior, based on a set of Input/Output data, in order to characterize it without necessarily a prior knowledge of any deterministic mechanism (system identification). In this context, data series collected by continuous hydrological monitoring instrumentation installed in the studied sites, together with meteorological and water extraction data, have been analyzed in order to assess the applicability and performance of a predictive model of the groundwater level. A mixed approach (both data driven and process-based) has been experimented on the whole dataset relating to the last ten years of continuous monitoring activity. The system identification approach presented here is based on the integration of an adaptive technique based on Artificial Neural Networks (ANNs) and a blind deterministic identification approach. According to this concept, the behavior of

  5. Induced infiltration from the Rockaway River and water chemistry in a stratified-drift aquifer at Dover, New Jersey, with a section on modeling ground-water flow in the Rockaway River Valley

    Science.gov (United States)

    Dysart, Joel E.; Rheaume, Stephen J.; Kontis, Angelo L.

    1999-01-01

    The vertical hydraulic conductivity per unit thickness (streambed leakance) of unconsolidated sediment immediately beneath the channel of the Rockaway River near a municipal well field at Dover, N.J., is between 0.2 and 0.6 feet per day per foot and is probably near the low end of this range. This estimate is based on evaluation of three lines of evidence: (1) Streamflow measurements, which indicated that induced infiltration of river water near the well field averaged 0.67 cubic feet per second; (2) measurements of the rate of downward propagation of diurnal fluctuations in dissolved oxygen and water temperature at three piezometers, which indicated vertical Darcian flow velocities of 0.6 and 1.5 feet per day, respectively; and (3) chemical mixing models based on stable isotopes of oxygen and hydrogen, which indicated that 30 percent of the water reaching a well near the center of the well field was derived from the river. The estimated streambed-leakance values are compatible with other aquifer properties and with hydraulic stresses observed over a 2-year period, as demonstrated by a set of six alternative groundwater flow models of the Rockaway River valley. Simulated water levels rose 0.5 to 1.7 feet near the well field when simulated streambed leakance was changed from 0.2 to 0.6 feet per day per foot, or when a former reach of the Rockaway River valley that is now blocked by glacial drift was simulated as containing a continuous sand aquifer (rather than impermeable till). Model recalibration to observed water levels could accommodate either of these changes, however, by plausible adjustments in hydraulic conductivity of 35 percent or less.The ground-water flow models incorporate a new procedure for simulating areal recharge, in which water available for recharge in any time interval is accepted as recharge only where the water level in the uppermost model layer is below land surface. Water rejected as recharge on upland hillsides is allowed to recharge

  6. Hydrogeology and ground-water/surface water interactions in the Des Moines River valley, southwestern Minnesota, 1997-2001

    Science.gov (United States)

    Cowdery, Timothy K.

    2005-01-01

    Increased water demand in and around Windom led the U.S. Geological Survey, in cooperation with the Minnesota Department of Natural Resources, local water suppliers, and Cottonwood County, to study the hydrology of aquifers in the Des Moines River Valley near Windom. The study area is the watershed of a 30-kilometer (19-mile) reach of the Des Moines River upstream from Windom.

  7. Yakima River Species Interactions Studies, Annual Report 1998

    International Nuclear Information System (INIS)

    Pearsons, Todd N.; Ham, Kenneth D.; McMichael, Geoffrey A.

    1999-01-01

    Species interactions research and monitoring was initiated in 1989 to investigate ecological interactions among fish in response to proposed supplementation of salmon and steelhead in the upper Yakima River basin. This is the seventh of a series of progress reports that address species interactions research and pre-supplementation monitoring of fishes in the Yakima River basin. Data have been collected prior to supplementation to characterize the ecology and demographics of non-target taxa (NTT) and target taxon, and develop methods to monitor interactions and supplementation success. Major topics of this report are associated with monitoring potential impacts to support adaptive management of NTT and baseline monitoring of fish predation indices on spring chinook salmon smolts. This report is organized into three chapters, with a general introduction preceding the first chapter. This annual report summarizes data collected primarily by the Washington Department of Fish and Wildlife (WDFW) between January 1, 1998 and December 31, 1998 in the Yakima basin, however these data were compared to data from previous years to identify preliminary trends and patterns

  8. Environmental isotope-aided studies on river water and groundwater interaction in the region of Seoul and Taegu

    International Nuclear Information System (INIS)

    Jong Sung Ahn

    1987-09-01

    The report provides the results and evaluations of environmental isotope analyses (O-18, H-2, H-3) undertaken in detailed field investigations carried out in the Han River Basin to study the hydrodynamics of river water and groundwater interrelationships. The conducted study, particularly near the Seoul area and the Taegu area, has enabled the delineation of the origin of groundwater in crystalline rock aquifers and limestone aquifers of the Han River Basin and evaluations as regards the groundwater flow dynamics based on environmental isotope data are given in the report. Refs, figs, tabs

  9. Impact of river restoration on groundwater - surface water - interactions

    Science.gov (United States)

    Kurth, Anne-Marie; Schirmer, Mario

    2014-05-01

    Since the end of the 19th century, flood protection was increasingly based on the construction of impermeable dams and side walls (BWG, 2003). In spite of providing flood protection, these measures also limited the connectivity between the river and the land, restricted the area available for flooding, and hampered the natural flow dynamics of the river. Apart from the debilitating effect on riverine ecosystems due to loss of habitats, these measures also limited bank filtration, inhibited the infiltration of storm water, and affected groundwater-surface water-interactions. This in turn had a profound effect on ecosystem health, as a lack of groundwater-surface water interactions led to decreased cycling of pollutants and nutrients in the hyporheic zone and limited the moderation of the water temperature (EA, 2009). In recent decades, it has become apparent that further damages to riverine ecosystems must be prohibited, as the damages to ecology, economy and society surmount any benefits gained from exploiting them. Nowadays, the restoration of rivers is a globally accepted means to restore ecosystem functioning, protect water resources and amend flood protection (Andrea et al., 2012; Palmer et al., 2005; Wortley et al., 2013). In spite of huge efforts regarding the restoration of rivers over the last 30 years, the question of its effectiveness remains, as river restorations often reconstruct a naturally looking rather than a naturally functioning stream (EA, 2009). We therefore focussed our research on the effectiveness of river restorations, represented by the groundwater-surface water-interactions. Given a sufficiently high groundwater level, a lack of groundwater-surface water-interactions after restoration may indicate that the vertical connectivity in the stream was not fully restored. In order to investigate groundwater-surface water-interactions we determined the thermal signature on the stream bed and in +/- 40 cm depth by using Distributed Temperature

  10. Development of a regional groundwater flow model for the area of the Idaho National Engineering Laboratory, Eastern Snake River Plain Aquifer

    International Nuclear Information System (INIS)

    McCarthy, J.M.; Arnett, R.C.; Neupauer, R.M.

    1995-03-01

    This report documents a study conducted to develop a regional groundwater flow model for the Eastern Snake River Plain Aquifer in the area of the Idaho National Engineering Laboratory. The model was developed to support Waste Area Group 10, Operable Unit 10-04 groundwater flow and transport studies. The products of this study are this report and a set of computational tools designed to numerically model the regional groundwater flow in the Eastern Snake River Plain aquifer. The objective of developing the current model was to create a tool for defining the regional groundwater flow at the INEL. The model was developed to (a) support future transport modeling for WAG 10-04 by providing the regional groundwater flow information needed for the WAG 10-04 risk assessment, (b) define the regional groundwater flow setting for modeling groundwater contaminant transport at the scale of the individual WAGs, (c) provide a tool for improving the understanding of the groundwater flow system below the INEL, and (d) consolidate the existing regional groundwater modeling information into one usable model. The current model is appropriate for defining the regional flow setting for flow submodels as well as hypothesis testing to better understand the regional groundwater flow in the area of the INEL. The scale of the submodels must be chosen based on accuracy required for the study

  11. Distribution of {sup 36}Cl/Cl in a river-recharged aquifer: Implications for the fallout rate of bomb-produced {sup 36}Cl

    Energy Technology Data Exchange (ETDEWEB)

    Tosaki, Yuki, E-mail: tosaki@tac.tsukuba.ac.j [Sustainable Environmental Studies, Graduate School of Life and Environmental Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8572 (Japan); Massmann, Gudrun [Institute of Geological Sciences, Department of Earth Sciences, Freie Universitaet Berlin, Malteserstrasse 74-100, 12249 Berlin (Germany); Tase, Norio [Sustainable Environmental Studies, Graduate School of Life and Environmental Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8572 (Japan); Sasa, Kimikazu; Takahashi, Tsutomu [Tandem Accelerator Complex, Research Facility Center for Science and Technology, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8577 (Japan); Matsushi, Yuki [Department of Nuclear Engineering and Management, School of Engineering, University of Tokyo, 2-11-16 Yayoi, Bunkyo-ku, Tokyo 113-0032 (Japan); Tamari, Michiko [Department of Chemistry, Graduate School of Pure and Applied Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8571 (Japan); Nagashima, Yasuo [Tandem Accelerator Complex, Research Facility Center for Science and Technology, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8577 (Japan); Bessho, Kotaro; Matsumura, Hiroshi [Radiation Science Center, High Energy Accelerator Research Organization (KEK), 1-1 Oho, Tsukuba, Ibaraki 305-0801 (Japan)

    2010-04-15

    Distribution of {sup 36}Cl/Cl ratios in a river-recharged aquifer was investigated in the Oderbruch area, northeastern Germany. The aquifer is confined up to 3.5-4 km inland, where it changes to an unconfined condition. The {sup 36}Cl/Cl ratios in the confined area were in the range between 4.6 x 10{sup -14} and 23.1 x 10{sup -14}, showing a peak at 2-3 km away from the river. A plot of {sup 36}Cl/Cl vs. reciprocal Cl{sup -} concentrations indicated possible effect of the Cl{sup -} concentration variation on the observed {sup 36}Cl/Cl ratios. After accounting for this effect, the estimated {sup 36}Cl fallout rates for the last 30 yrs show reasonable agreement with the Dye-3 data and the mid-latitude background value. The results suggest that a local {sup 36}Cl fallout curve can be constructed from groundwater when dispersive mixing is of minor importance.

  12. Rock–water interactions and pollution processes in the volcanic aquifer system of Guadalajara, Mexico, using inverse geochemical modeling

    International Nuclear Information System (INIS)

    Morán-Ramírez, J.; Ledesma-Ruiz, R.; Mahlknecht, J.; Ramos-Leal, J.A.

    2016-01-01

    In order to understand and mitigate the deterioration of water quality in the aquifer system underlying Guadalajara metropolitan area, an investigation was performed developing geochemical evolution models for assessment of groundwater chemical processes. The models helped not only to conceptualize the groundwater geochemistry, but also to evaluate the relative influence of anthropogenic inputs and natural sources of salinity to the groundwater. Mixing processes, ion exchange, water–rock–water interactions and nitrate pollution and denitrification were identified and confirmed using mass-balance models constraint by information on hydrogeology, groundwater chemistry, lithology and stability of geochemical phases. The water–rock interactions in the volcanic setting produced a dominant Na−HCO_3 water type, followed by Na−Mg−Ca−HCO_3 and Na−Ca−HCO_3. For geochemical evolution modeling, flow sections were selected representing recharge and non-recharge processes and a variety of mixing conditions. Recharge processes are dominated by dissolution of soil CO_2 gas, calcite, gypsum, albite and biotite, and Ca/Na exchange. Non-recharge processes show that the production of carbonic acid and Ca/Na exchange are decreasing, while other minerals such as halite and amorphous SiO_2 are precipitated. The origin of nitrate pollution in groundwater are fertilizers in rural plots and wastewater and waste disposal in the urban area. This investigation may help water authorities to adequately address and manage groundwater contamination. - Highlights: • The Inverse geochemical modeling was used to study to processes occurring in a volcanic aquifer. • Three flow sections were selected to apply inverse hydrogeochemical modeling. • Three main groundwater flows were identified: a local, intermediate and regional flow. • The models show that in the study area that groundwater is mixed with local recharge. • In the south, the aquifer has thermal influence.

  13. Hydrological and geochemical consequences of river regulation - hyporheic perspective

    Science.gov (United States)

    Siergieiev, Dmytro; Lundberg, Angela; Widerlund, Anders

    2014-05-01

    River-aquifer interfaces, essential for ecosystem functioning in terms of nutrient exchange and biological habitat, appear greatly threatened worldwide. Although river regulation is a vast pressure on river-aquifer interaction, influencing entire watersheds, knowledge about hyporheic exchange in regulated rivers is rather limited. In this study, we combine two decades of research on hydrological and geochemical impacts of hydropower regulation on river water and hyporheic zone in two large boreal rivers, unregulated Kalix River and regulated Lule River. Altered river discharge, with reduced spring peaks, daily summer fluctuations and elevated winter base flow severely modified Lule River water geochemistry and thus the transport of solutes to the Bothnian Bay (Baltic Sea). Further, these river modifications changed the river-aquifer exchange on both daily and seasonal scale, which resulted in deteriorated hyporheic conditions with reduced riverbed hydraulic conductivity (formation of a clogging layer) reflected in a declined hyporheic flux. Altered hydrological regime of the hyporheic zone created quasi-stagnant conditions beneath the river-aquifer interface and promoted the formation of geochemically suboxic environment. Taken that hyporheic water is a mixture of river water and groundwater, mixing models for the regulated site demonstrate a considerable addition of Fe, Mn, Al, NH4 and removal of dissolved oxygen and nitrate, which suggests the hyporheic zone in the Lule River to be a source of solutes. This contradicts the observations from the hyporheic zone in the unregulated river, with opposite behaviour functioning as a barrier. These results suggest that the hyporheic zone function is dependent on the river discharge and the state of the river-aquifer connectivity. Improved knowledge about the latter on a watershed scale will substantially increase our understanding about the status and potential pressures of riverine ecosystems and assist management and

  14. Geology and ground-water conditions of Clark County Washington, with a description of a major alluvial aquifer along the Columbia River

    Science.gov (United States)

    Mundorff, Maurice John

    1964-01-01

    This report presents the results of an investigation of the ground-water resources of the populated parts of Clark County. Yields adequate for irrigation can be obtained from wells inmost farmed areas in Clark County, Wash. The total available supply is sufficient for all foreseeable irrigation developments. In a few local areas aquifers are fine-grained, and yields of individual wells are low. An enormous ground-water supply is available from a major alluvial aquifer underlying the flood plain of the Columbia River in the vicinity of Vancouver, Camas, and Washougal, where the aquifer is recharged, in part, by infiltration from the river. Yields of individual wells are large, ranging to as much as 4,000 gpm (gallons per minute). Clark County lies along the western flank of the Cascade Range. in the structural lowland (Willamette-Puget trough) between those mountains and the Coast Ranges to the west. The area covered by the report includes the urban, the suburban, and most of the agricultural lands in the county. These lands lie on a Series of nearly fiat plains and benches which rise steplike from the level of the Columbia River (a few feet above sea level) to about 800 feet above sea level. Clark County is-drained by the Columbia River (the trunk stream of the Pacific Northwest) and its tributaries. The Columbia River forms the southern and western boundaries of the county. Although the climate of the county is considered to be humid, the precipitation ranging from about 37 to more than 110 inches annually in various parts of the county, the unequal seasonal distribution (about 1.5 inches total for ;July and August in the agricultural area) makes irrigation highly desirable for most .crops and essential for some specialized crops. Consolidated rocks of Eocene to Miocene age, chiefly volcanic lava flows and pyroclastics but including some sedimentary strata, crop out in the foothills of the Cascades in the eastern part of the county and underlie the younger

  15. Comment on An Alternative View on the Origin of Chemical and Isotopic Patterns in Groundwater From the Milk River Aquifer, Canada by M.J. Hendry and F.W. Schwartz

    International Nuclear Information System (INIS)

    Phillips, F.M.; Knowlton, R.G.; Bentley, H.W.

    1990-01-01

    The Milk River aquifer in southern Alberta combines apparently simple, classical confined aquifer hydrodynamics with somewhat enigmatic groundwater geochemistry of conservative solutes. Over the past 10 years, five major papers have focused on the geochemistry of Milk River aquifer groundwater. Most recently, Hendry and Schwartz (1988) have proposed a different mechanism, aquitard diffusion, to explain the Milk River geochemistry. They described and evaluated previously proposed geochemical processes, especially ion filtration. Hendry and Schwartz (1988) concluded that ion filtration and the other proposed mechanisms were not supported by the data. They then described the aquitard diffusion mechanism and used a simple analytical model to simulate observed aquifer trends in Cl - and 18 O. From the results of this exercise they concluded that diffusion from the aquitards was controlling the solute distributions in the aquifer. Finally, they interpreted previously published 36 Cl data and new profiles of Cl - in the aquitards in terms of the diffusion model. Upon review, the authors do not find the arguments against ion filtration to be as damaging as Hendry and Schwartz indicate, nor do they find the evidence for aquitard diffusion to be as persuasive. In this study they will first evaluate Hendry and Schwartz's arguments against ion filtration, then they will review the arguments in favor of aquitard diffusion, and finally the authors will address the implications for the interpretation of the vertical Cl - profiles and the 36 Cl data

  16. A New Streamflow-Routing (SFR1) Package to Simulate Stream-Aquifer Interaction with MODFLOW-2000

    Science.gov (United States)

    Prudic, David E.; Konikow, Leonard F.; Banta, Edward R.

    2004-01-01

    The increasing concern for water and its quality require improved methods to evaluate the interaction between streams and aquifers and the strong influence that streams can have on the flow and transport of contaminants through many aquifers. For this reason, a new Streamflow-Routing (SFR1) Package was written for use with the U.S. Geological Survey's MODFLOW-2000 ground-water flow model. The SFR1 Package is linked to the Lake (LAK3) Package, and both have been integrated with the Ground-Water Transport (GWT) Process of MODFLOW-2000 (MODFLOW-GWT). SFR1 replaces the previous Stream (STR1) Package, with the most important difference being that stream depth is computed at the midpoint of each reach instead of at the beginning of each reach, as was done in the original Stream Package. This approach allows for the addition and subtraction of water from runoff, precipitation, and evapotranspiration within each reach. Because the SFR1 Package computes stream depth differently than that for the original package, a different name was used to distinguish it from the original Stream (STR1) Package. The SFR1 Package has five options for simulating stream depth and four options for computing diversions from a stream. The options for computing stream depth are: a specified value; Manning's equation (using a wide rectangular channel or an eight-point cross section); a power equation; or a table of values that relate flow to depth and width. Each stream segment can have a different option. Outflow from lakes can be computed using the same options. Because the wetted perimeter is computed for the eight-point cross section and width is computed for the power equation and table of values, the streambed conductance term no longer needs to be calculated externally whenever the area of streambed changes as a function of flow. The concentration of solute is computed in a stream network when MODFLOW-GWT is used in conjunction with the SFR1 Package. The concentration of a solute in a

  17. An update of hydrologic conditions and distribution of selected constituents in water, eastern Snake River Plain aquifer and perched groundwater zones, Idaho National Laboratory, Idaho, emphasis 2012-15

    Science.gov (United States)

    Bartholomay, Roy C.; Maimer, Neil V.; Rattray, Gordon W.; Fisher, Jason C.

    2017-04-10

    Since 1952, wastewater discharged to in ltration ponds (also called percolation ponds) and disposal wells at the Idaho National Laboratory (INL) has affected water quality in the eastern Snake River Plain (ESRP) aquifer and perched groundwater zones underlying the INL. The U.S. Geological Survey (USGS), in cooperation with the U.S. Department of Energy, maintains groundwater-monitoring networks at the INL to determine hydrologic trends and to delineate the movement of radiochemical and chemical wastes in the aquifer and in perched groundwater zones. This report presents an analysis of water-level and water-quality data collected from the ESRP aquifer, multilevel monitoring system (MLMS) wells in the ESRP aquifer, and perched groundwater wells in the USGS groundwater monitoring networks during 2012-15.

  18. GEOCHEMICAL ASSESSMENT OF THE UNCONFINED AQUIFER IN A RECENTLY RECLAIMED WETLAND AREA: A CASE STUDY FROM THE PO RIVER DELTA

    Directory of Open Access Journals (Sweden)

    Dario Di Giuseppe

    2013-09-01

    Full Text Available This study focusses on the distribution of main anions and nitrogen species in the unconfined aquifer of a recently reclaimed land. In a 6 ha experimental field, 10 piezometers for water level measurement and groundwater sampling have been installed. After one year of monitoring, results show that the high chloride and ammonium concentrations are due to inherited from the previous brackish conditions and to organic matter mineralization, respectively. Seasonal variations and Cl/Br ratio show that the 1 m deep sub surface drainage system is the main factor conditioning the chemical characteristics and the piezometric depth of the aquifer

  19. Vertical variability of arsenic concentrations under the control of iron-sulfur-arsenic interactions in reducing aquifer systems

    Science.gov (United States)

    Pi, Kunfu; Wang, Yanxin; Postma, Dieke; Ma, Teng; Su, Chunli; Xie, Xianjun

    2018-06-01

    High spatial variability of arsenic (As) concentration in geogenic As-contaminated groundwater has been commonly observed worldwide, but the underlying reasons remain not well understood. Selecting a sulfate-containing, As-affected aquifer at the Datong Basin, northern China as the study area and combining hydrogeochemical investigation and sediment extraction with reactive transport modeling, this work elucidated the roles of Fe-S-As interactions in regulating the vertical variation of As concentration in the groundwater. Dissolved As concentration varied between 0.05 and 18 μmol/L, but generally increased in the depth of 20-25 m and then decreased in 25-30 m. The high-As groundwater contained low Fe(II) (groundwater devoid of sulfate reduction. The reductive dissolution of As-bearing Fe(III) oxides coupled to the degradation of organic matter with an estimated maximum rate of 0.22 mmol C/L/yr, mainly accounted for the depth-dependent increase of As concentration in the upper part of the shallow aquifer (groundwater but also probably co-precipitated As to prompt As decrease in the depth of 25-30 m. Arsenite adsorbed on remaining Fe(III) oxides and newly-formed Fe(II) sulfides is another important pool of As in the aquifer, which varies in response to the extents of Fe(III)-oxide and sulfate reduction and consequently alters As distribution coefficient between the solid and the aqueous phases. This study highlights the importance of coupled geochemical cycling of Fe, S and As for As mobilization and reveals how it regulates As partitioning between groundwater and sediments.

  20. Simulation of the Regional Ground-Water-Flow System and Ground-Water/Surface-Water Interaction in the Rock River Basin, Wisconsin

    Science.gov (United States)

    Juckem, Paul F.

    2009-01-01

    A regional, two-dimensional, areal ground-water-flow model was developed to simulate the ground-water-flow system and ground-water/surface-water interaction in the Rock River Basin. The model was developed by the U.S. Geological Survey (USGS), in cooperation with the Rock River Coalition. The objectives of the regional model were to improve understanding of the ground-water-flow system and to develop a tool suitable for evaluating the effects of potential regional water-management programs. The computer code GFLOW was used because of the ease with which the model can simulate ground-water/surface-water interactions, provide a framework for simulating regional ground-water-flow systems, and be refined in a stepwise fashion to incorporate new data and simulate ground-water-flow patterns at multiple scales. The ground-water-flow model described in this report simulates the major hydrogeologic features of the modeled area, including bedrock and surficial aquifers, ground-water/surface-water interactions, and ground-water withdrawals from high-capacity wells. The steady-state model treats the ground-water-flow system as a single layer with hydraulic conductivity and base elevation zones that reflect the distribution of lithologic groups above the Precambrian bedrock and a regionally significant confining unit, the Maquoketa Formation. In the eastern part of the Basin where the shale-rich Maquoketa Formation is present, deep ground-water flow in the sandstone aquifer below the Maquoketa Formation was not simulated directly, but flow into this aquifer was incorporated into the GFLOW model from previous work in southeastern Wisconsin. Recharge was constrained primarily by stream base-flow estimates and was applied uniformly within zones guided by regional infiltration estimates for soils. The model includes average ground-water withdrawals from 1997 to 2006 for municipal wells and from 1997 to 2005 for high-capacity irrigation, industrial, and commercial wells. In addition

  1. Effects of Fenton's Reagent on aquifer geochemistry and microbiology at the A/M Area, Savannah River Site

    International Nuclear Information System (INIS)

    Denham, M.

    2000-01-01

    This report details the results of an investigation of Site conditions following a successful 1997 demonstration of in-situ DNAPL destruction by injection of Fenton's Reagent (hydrogen peroxide and ferrous sulfate solution) into DNAPL-bearing zones of an aquifer

  2. Hydrogeology and water quality in the Snake River alluvial aquifer at Jackson Hole Airport, Jackson, Wyoming, water years 2011 and 2012

    Science.gov (United States)

    Wright, Peter R.

    2013-01-01

    The hydrogeology and water quality of the Snake River alluvial aquifer at the Jackson Hole Airport in northwest Wyoming was studied by the U.S. Geological Survey, in cooperation with the Jackson Hole Airport Board, during water years 2011 and 2012 as part of a followup to a previous baseline study during September 2008 through June 2009. Hydrogeologic conditions were characterized using data collected from 19 Jackson Hole Airport wells. Groundwater levels are summarized in this report and the direction of groundwater flow, hydraulic gradients, and estimated groundwater velocity rates in the Snake River alluvial aquifer underlying the study area are presented. Analytical results of groundwater samples collected from 10 wells during water years 2011 and 2012 are presented and summarized. The water table at Jackson Hole Airport was lowest in early spring and reached its peak in July or August, with an increase of 12.5 to 15.5 feet between April and July 2011. Groundwater flow was predominantly horizontal but generally had the hydraulic potential for downward flow. Groundwater flow within the Snake River alluvial aquifer at the airport was from the northeast to the west-southwest, with horizontal velocities estimated to be about 25 to 68 feet per day. This range of velocities slightly is broader than the range determined in the previous study and likely is due to variability in the local climate. The travel time from the farthest upgradient well to the farthest downgradient well was approximately 52 to 142 days. This estimate only describes the average movement of groundwater, and some solutes may move at a different rate than groundwater through the aquifer. The quality of the water in the alluvial aquifer generally was considered good. Water from the alluvial aquifer was fresh, hard to very hard, and dominated by calcium carbonate. No constituents were detected at concentrations exceeding U.S. Environmental Protection Agency maximum contaminant levels or health

  3. An update of hydrologic conditions and distribution of selected constituents in water, Snake River Plain aquifer and perched groundwater zones, Idaho National Laboratory, Idaho, emphasis 2006-08

    Science.gov (United States)

    Davis, Linda C.

    2010-01-01

    Since 1952, radiochemical and chemical wastewater discharged to infiltration ponds (also called percolation ponds), evaporation ponds, and disposal wells at the Idaho National Laboratory (INL) has affected water quality in the eastern Snake River Plain aquifer and perched groundwater zones underlying the INL. The U.S. Geological Survey, in cooperation with the U.S. Department of Energy, maintains groundwater monitoring networks at the INL to determine hydrologic trends, and to delineate the movement of radiochemical and chemical wastes in the aquifer and in perched groundwater zones. This report presents an analysis of water-level and water-quality data collected from aquifer and perched groundwater wells in the USGS groundwater monitoring networks during 2006-08. Water in the Snake River Plain aquifer primarily moves through fractures and interflow zones in basalt, generally flows southwestward, and eventually discharges at springs along the Snake River. The aquifer primarily is recharged from infiltration of irrigation water, infiltration of streamflow, groundwater inflow from adjoining mountain drainage basins, and infiltration of precipitation. From March-May 2005 to March-May 2008, water levels in wells generally remained constant or rose slightly in the southwestern corner of the INL. Water levels declined in the central and northern parts of the INL. The declines ranged from about 1 to 3 feet in the central part of the INL, to as much as 9 feet in the northern part of the INL. Water levels in perched groundwater wells around the Advanced Test Reactor Complex (ATRC) also declined. Detectable concentrations of radiochemical constituents in water samples from wells in the Snake River Plain aquifer at the INL generally decreased or remained constant during 2006-08. Decreases in concentrations were attributed to decreased rates of radioactive-waste disposal, radioactive decay, changes in waste-disposal methods, and dilution from recharge and underflow. In April

  4. Water-rock interaction and geochemistry of groundwater from the Ain Azel aquifer, Algeria.

    Science.gov (United States)

    Belkhiri, Lazhar; Mouni, Lotfi; Tiri, Ammar

    2012-02-01

    Hydrochemical, multivariate statistical, and inverse geochemical modeling techniques were used to investigate the hydrochemical evolution within the Ain Azel aquifer, Algeria. Cluster analysis based on major ion contents defined 3 main chemical water types, reflecting different hydrochemical processes. The first group water, group 1, has low salinity (mean EC = 735 μS/cm). The second group waters are classified as Cl-HCO(3)-alkaline earth type. The third group is made up of water samples, the cation composition of which is dominated by Ca and Mg with anion composition varying from dominantly Cl to dominantly HCO(3) plus SO(4). The varifactors obtained from R-mode FA indicate that the parameters responsible for groundwater quality variations are mainly related to the presence and dissolution of some carbonate, silicate, and evaporite minerals in the aquifer. Inverse geochemical modeling along groundwater flow paths indicates the dominant processes are the consumption of CO(2), the dissolution of dolomite, gypsum, and halite, along with the precipitation of calcite, Ca-montmorillonite, illite, kaolinite, and quartz. © Springer Science+Business Media B.V. 2011

  5. Combining hydrologic and groundwater modelling to characterize a regional aquifer system within a rift setting (Gidabo River Basin, Main Ethiopian Rift)

    Science.gov (United States)

    Birk, Steffen; Mechal, Abraham; Wagner, Thomas; Dietzel, Martin; Leis, Albrecht; Winkler, Gerfried; Mogessie, Aberra

    2016-04-01

    The development of groundwater resources within the Ethiopian Rift is complicated by the strong physiographic contrasts between the rift floor and the highland and by the manifold hydrogeological setting composed of volcanic rocks of different type and age that are intersected by numerous faults. Hydrogeochemical and isotope data from various regions within the Ethiopian Rift suggest that the aquifers within the semi-arid rift floor receive a significant contribution of groundwater flow from the humid highland. For example, the major ion composition of groundwater samples from Gidabo River Basin (3302 km²) in the southern part of the Main Ethiopian Rift reveals a mixing trend from the highland toward the rift floor; moreover, the stable isotopes of water, deuterium and O-18, of the rift-floor samples indicate a component recharged in the highland. This work aims to assess if the hydrological and hydrogeological data available for Gidabo River Basin is consistent with these findings and to characterize the regional aquifer system within the rift setting. For this purpose, a two-step approach is employed: First, the semi-distributed hydrological model SWAT is used to obtain an estimate of the spatial and temporal distribution of groundwater recharge within the watershed; second, the numerical groundwater flow model MODFLOW is employed to infer aquifer properties and groundwater flow components. The hydrological model was calibrated and validated using discharge data from three stream gauging stations within the watershed (Mechal et al., Journal of Hydrology: Regional Studies, 2015, doi:10.1016/j.ejrh.2015.09.001). The resulting recharge distribution exhibits a strong decrease from the highland, where the mean annual recharge amounts to several hundred millimetres, to the rift floor, where annual recharge largely is around 100 mm and below. Using this recharge distribution as input, a two-dimensional steady-state groundwater flow model was calibrated to hydraulic

  6. Spatio-temporal variation of stream-aquifer interaction: Effect of a weir construction in Korea

    Science.gov (United States)

    Lee, Hyeonju; Koo, Min-Ho; Kim, Kisu; Kim, Yongcheol

    2015-04-01

    The Four Major Rivers Restoration Project was conducted to secure sufficient water resources, introduce comprehensive flood control measures, and improve water quality while restore the river ecosystem in Korea. The dredging of river bed and the installation of 16 weirs were done in Han, Geum, Yeongsan, and Nakdong rivers from late 2010 to early 2012 as a part of the project. Groundwater data obtained from 213 groundwater monitoring wells near the four major rivers were used to analyze the impacts of weir construction on the nearby groundwater flow system. The groundwater level and chemical characteristics were analyzed to investigate how the groundwater flow system and water quality changed after the weir construction. The results showed that groundwater level rose immediately following the rise of stream stage after the weir construction. Also, the hydrologic condition of the stream in some upland of the weirs was changed from a gaining to a losing stream. Consequently, the direction of groundwater flow was changed from perpendicular to parallel to the stream, and it swapped the groundwater in the downstream of the weir for the water recharged from the stream. Considering the results, some groundwater quality is expected to be changed and become similar to that of the stream, although the change has been not observed yet. Therefore, both further monitoring of the groundwater quality and hydrogeochemical analysis are required for quantitatively evaluating the effect of the weir.

  7. Vertical variation in groundwater chemistry inferred from fluid specific-conductance well logging of the Snake River Plain Basalt aquifer, Idaho National Engineering Laboratory, southeastern Idaho

    International Nuclear Information System (INIS)

    Wood, S.H.; Bennecke, W.

    1994-01-01

    Well logging of electrical fluid specific conductance (C s ) shows that permeable zones yielding ground water to intrawell flows and the water columns in some wells at INEL have highly different chemistry, with as much as a two-fold variation in C s . This suggests that dedicated-pump sampling of ground water in the aquifer may not be representative of the chemistry of the waste plumes migrating southwest of the nuclear facilities. Natural background C s in basalt-aquifer ground water of this part of the Snake River Plain aquifer is less than 325μS/cm (microSiemans/cm), and total dissolved solids in mg/L units, (TDS) ∼ 0.6C s . This relationship underestimates TDS for waters with chemical waste, when C s is above 800 μS/cm. At well 59 near the ICPP water of 1115 μS/cm (∼6570+ mg/L TDS) enters the well from a permeable zone between 521 and 537 ft depth; the zone being 60 ft below the water level and water of 550 μS/cm. At the time of logging (9/14/93) the 1115/μS/cm water was flowing down the well, mixing with less concentrated waters and exciting at 600 or 624-ft depth. Waste water disposed of down the injection well at ICPP until 1984 was estimated to have a C 5 of 1140 μS/cm, identical to the water detected in logging. 29 refs., 8 figs., 1 tab

  8. Determination of Background Uranium Concentration in the Snake River Plain Aquifer under the Idaho National Engineering and Environmental Laboratory's Radioactive Waste Management Complex

    International Nuclear Information System (INIS)

    Molly K. Leecaster; L. Don Koeppen; Gail L. Olson

    2003-01-01

    Uranium occurs naturally in the environment and is also a contaminant that is disposed of at the Radioactive Waste Management Complex (RWMC) at the Idaho National Engineering and Environmental Laboratory. To determine whether uranium concentrations in the Snake River Plain Aquifer, which underlies the laboratory, are elevated as a result of migration of anthropogenic uranium from the Subsurface Disposal Area in the RWMC, uranium background concentrations are necessary. Guideline values are calculated for total uranium, 234U, 235U, and 238U from analytical results from up to five datasets. Three of the datasets include results of samples analyzed using isotope dilution thermal ionization mass spectrometry (ID-TIMS) and two of the datasets include results obtained using alpha spectrometry. All samples included in the statistical testing were collected from aquifer monitoring wells located within 10 miles of the RWMC. Results from ID-TIMS and alpha spectrometry are combined when the data are not statistically different. Guideline values for total uranium were calculated using four of the datasets, while guideline values for 234U were calculated using only the alpha spectrometry results (2 datasets). Data from all five datasets were used to calculate 238U guideline values. No limit is calculated for 235U because the ID-TIMS results are not useful for comparison with routine monitoring data, and the alpha spectrometry results are too close to the detection limit to be deemed accurate or reliable for calculating a 235U guideline value. All guideline values presented represent the upper 95% coverage 95% confidence tolerance limits for background concentration. If a future monitoring result is above this guideline, then the exceedance will be noted in the quarterly monitoring report and assessed with respect to other aquifer information. The guidelines (tolerance limits) for total U, 234U, and 238U are 2.75 pCi/L, 1.92 pCi/L, and 0.90 pCi/L, respectively

  9. Assessment of groundwater recharge and water fluxes of the Guarani Aquifer System, Brazil

    Science.gov (United States)

    Rabelo, Jorge Luiz; Wendland, Edson

    2009-11-01

    The groundwater recharge and water fluxes of the Guarani Aquifer System in the state of Sao Paulo in Brazil were assessed through a numeric model. The study area (6,748 km2) comprises Jacaré-Guaçú and Jacaré-Pepira River watersheds, tributaries of the Tietê River in the central region of the state. GIS based tools were used in the storage, processing and analysis of data. Main hydrologic phenomena were selected, leading to a groundwater conceptual model, taking into account the significant outcrops occurring in the study area. Six recharge zones were related to the geologic formation and structures of the semi-confined and phreatic aquifer. The model was calibrated against the baseflows and static water levels of the wells. The results emphasize the strong interaction of groundwater flows between watersheds and the groundwater inflow into the rivers. It has been concluded that lateral groundwater exchanges between basins, the deep discharges to the regional system, and well exploitation were not significant aquifer outflows when compared to the aquifer recharge. The results have shown that the inflows from the river into the aquifer are significant and have the utmost importance since the aquifer is potentially more vulnerable in these places.

  10. Drivers and Effects of Groundwater-Surface Water Interaction in the Karstic Lower Flint River Basin, Southwestern Georgia, USA

    Science.gov (United States)

    Rugel, K.; Golladay, S. W.; Jackson, C. R.; Rasmussen, T. C.; Dowd, J. F.; Mcdowell, R. J.

    2017-12-01

    Groundwater provides the majority of global water resources for domestic and agricultural usage while contributing vital surface water baseflows which support healthy aquatic ecosystems. Understanding the extent and magnitude of hydrologic connectivity between groundwater and surface water components in karst watersheds is essential to the prudent management of these hydraulically-interactive systems. We examined groundwater and surface water connectivity between the Upper Floridan Aquifer (UFA) and streams in the Lower Flint River Basin (LFRB) in southwestern Georgia where development of agricultural irrigation intensified over the past 30 years. An analysis of USGS streamflow data for the pre- and post-irrigation period showed summer baseflows in some Lower Flint River tributaries were reduced by an order of magnitude in the post-irrigation period, reiterating the strong hydraulic connection between these streams and the underlying aquifer. Large and fine-scale monitoring of calcium, nitrate, specific conductance and stable isotopes (δ18O and δD) on 50 km of Ichawaynochaway Creek, a major tributary of the Lower Flint, detected discrete groundwater-surface water flow paths which accounted for 42% of total groundwater contributions in the 50 km study reach. This presentation will highlight a new analysis using the metadata EPA Reach File (1) and comparing stream reach and instream bedrock joint azimuths with stream geochemical results from previous field study. Our findings suggested that reaches with NNW bearing may be more likely to display enhanced groundwater-surface water connectivity. Our results show that local heterogeneity can significantly affect water budgets and quality within these watersheds, making the use of geomorphological stream attributes a valuable tool to water resource management for the prediction and protection of vulnerable regions of hydrologic connectivity in karst catchments.

  11. Hydrostratigraphy of the Snake River Plain aquifer beneath the Radioactive Waste Management Complex at the Idaho National Engineering Laboratory: A preliminary report

    International Nuclear Information System (INIS)

    Hegmann, M.J.; Wood, S.H.

    1994-01-01

    Geophysical logs for 6 wells which penetrate the Snake River Plain aquifer at the Radioactive Waste Management Complex (RWMC) were analyzed for preliminary information on the hydrostratigraphy. Using stratigraphic correlation of flow groups worked out by Anderson and Lewis (1989), and by Anderson, as well as gamma signatures of flows within these flow groups, correlation of individual flows is attempted. Within these flows, probable permeable zones, suggested by density and caliper logs, are identified, and zones of hydraulic connection are tentatively correlated. In order to understand the response of density and neutron logs in basalt, the geological characteristics are quantified for the 150-ft section of the well C1A core, from depth 550 to 710 ft. 9 refs., 4 figs

  12. The interaction between the unsaturated zone, aquifer, and stream during a period of groundwater withdrawal

    DEFF Research Database (Denmark)

    Poulsen, Søren Erbs; Christensen, Steen; Rasmussen, Keld Rømer

    2011-01-01

    drainage responses to water-table drawdown. The responses can be sufficiently modeled by estimating the specific yield and five exponential time constants of a Moench/Boulton type model of delayed drainage. The average specific yield is thus estimated to 0.24 which is in agreement with previous small scale......; in the second case the estimate (0.17) is in better agreement with core and previous estimates (0.24). The analysis indicates that relatively fast drainage, and the existence of two drawdown dependent sources of groundwater recharge (the storage and the stream), complicates pumping test design to obtain unique...... parameter estimation. The analysis supports that an essential factor in parameter estimation by pumping test analysis for (at least some) unconfined aquifers is the use of a model that accounts for time-varying drainage from the vadose zone. Finally, when predicting stream depletion beyond 1. day of pumping...

  13. Application of Surface Geophysical Methods, With Emphasis on Magnetic Resonance Soundings, to Characterize the Hydrostratigraphy of the Brazos River Alluvium Aquifer, College Station, Texas, July 2006 - A Pilot Study

    Science.gov (United States)

    Shah, Sachin D.; Kress, Wade H.; Legchenko, Anatoly

    2007-01-01

    The U.S. Geological Survey, in cooperation with the Texas Water Development Board, used surface geophysical methods at the Texas A&M University Brazos River Hydrologic Field Research Site near College Station, Texas, in a pilot study, to characterize the hydrostratigraphic properties of the Brazos River alluvium aquifer and determine the effectiveness of the methods to aid in generating an improved ground-water availability model. Three non-invasive surface geophysical methods were used to characterize the electrical stratigraphy and hydraulic properties and to interpret the hydrostratigraphy of the Brazos River alluvium aquifer. Two methods, time-domain electromagnetic (TDEM) soundings and two-dimensional direct-current (2D-DC) resistivity imaging, were used to define the lateral and vertical extent of the Ships clay, the alluvium of the Brazos River alluvium aquifer, and the underlying Yegua Formation. Magnetic resonance sounding (MRS), a recently developed geophysical method, was used to derive estimates of the hydrologic properties including percentage water content and hydraulic conductivity. Results from the geophysics study demonstrated the usefulness of combined TDEM, 2D-DC resistivity, and MRS methods to reduce the need for additional boreholes in areas with data gaps and to provide more accurate information for ground-water availability models. Stratigraphically, the principal finding of this study is the relation between electrical resistivity and the depth and thickness of the subsurface hydrostratigraphic units at the site. TDEM data defined a three-layer electrical stratigraphy corresponding to a conductor-resistor-conductor that represents the hydrostratigraphic units - the Ships clay, the alluvium of the Brazos River alluvium aquifer, and the Yegua Formation. Sharp electrical boundaries occur at about 4 to 6 and 20 to 22 meters below land surface based on the TDEM data and define the geometry of the more resistive Brazos River alluvium aquifer

  14. An update of hydrologic conditions and distribution of selected constituents in water, Snake River Plain aquifer, Idaho National Laboratory, Idaho, Emphasis 1999-2001

    Science.gov (United States)

    Davis, Linda C.

    2006-01-01

    Radiochemical and chemical wastewater discharged since 1952 to infiltration ponds, evaporation ponds, and disposal wells at the Idaho National Laboratory (INL) has affected water quality in the Snake River Plain aquifer underlying the INL. The U.S. Geological Survey (USGS), in cooperation with the U.S. Department of Energy, maintains ground-water monitoring networks at the INL to determine hydrologic trends, and to delineate the movement of radiochemical and chemical wastes in the aquifer. This report presents an analysis of water-level and water-quality data collected from wells in the USGS ground-water monitoring networks during 1999-2001. Water in the Snake River Plain aquifer moves principally through fractures and interflow zones in basalt, generally flows southwestward, and eventually discharges at springs along the Snake River. The aquifer is recharged principally from infiltration of irrigation water, infiltration of streamflow, ground-water inflow from adjoining mountain drainage basins, and infiltration of precipitation. Water levels in wells rose in the northern and west-central parts of the INL by 1 to 3 feet, and declined in the southwestern parts of the INL by up to 4 feet during 1999-2001. Detectable concentrations of radiochemical constituents in water samples from wells in the Snake River Plain aquifer at the INL generally decreased or remained constant during 1999-2001. Decreases in concentrations were attributed to decreased rates of radioactive-waste disposal, radioactive decay, changes in waste-disposal methods, and dilution from recharge. Tritium concentrations in water samples decreased as much as 8.3 picocuries per milliliter (pCi/mL) during 1999-2001, ranging from 0.43?0.14 to 13.6?0.6 pCi/mL in October 2001. Tritium concentrations in five wells near the Idaho Nuclear Technology and Engineering Center (INTEC) increased a few picocuries per milliliter from October 2000 to October 2001. Strontium-90 concentrations decreased or remained

  15. local government headquarters and spatial interaction within rivers

    African Journals Online (AJOL)

    user

    headquarters and rural hinterland settlements in Rivers South East ... of Rivers State is responsible for over seventy percent (70%) of the total employment in the ... even proportion and balanced development for all could not completely ... Rivers West ... agricultural under development, unemployment, poor quality of life due.

  16. Investigating river–aquifer relations using water temperature in an anthropized environment (Motril-Salobreña aquifer)

    DEFF Research Database (Denmark)

    Duque, Carlos; Calvache, Marie; Engesgaard, Peter Knudegaard

    2010-01-01

    Heat was applied as a tracer for determining river–aquifer relations in the Motril-Salobreña aquifer (S Spain). The aquifer has typically been recharged by River Guadalfeo infiltration, nevertheless from 2005 a dam was constructed changing the traditional dynamic river flow and recharge events...

  17. Alluvial Aquifer

    Data.gov (United States)

    Kansas Data Access and Support Center — This coverage shows the extents of the alluvial aquifers in Kansas. The alluvial aquifers consist of unconsolidated Quaternary alluvium and contiguous terrace...

  18. In Situ Production of Chlorine-36 in the Eastern Snake River Plain Aquifer, Idaho: Implications for Describing Ground-Water Contamination Near a Nuclear Facility

    International Nuclear Information System (INIS)

    Cecil, L. D.; Knobel, L. L.; Green, J. R.; Frape, S. K.

    2000-01-01

    The purpose of this report is to describe the calculated contribution to ground water of natural, in situ produced 36Cl in the eastern Snake River Plain aquifer and to compare these concentrations in ground water with measured concentrations near a nuclear facility in southeastern Idaho. The scope focused on isotopic and chemical analyses and associated 36Cl in situ production calculations on 25 whole-rock samples from 6 major water-bearing rock types present in the eastern Snake River Plain. The rock types investigated were basalt, rhyolite, limestone, dolomite, shale, and quartzite. Determining the contribution of in situ production to 36Cl inventories in ground water facilitated the identification of the source for this radionuclide in environmental samples. On the basis of calculations reported here, in situ production of 36Cl was determined to be insignificant compared to concentrations measured in ground water near buried and injected nuclear waste at the INEEL. Maximum estimated 36Cl concentrations in ground water from in situ production are on the same order of magnitude as natural concentrations in meteoric water

  19. Probability of Elevated Volatile Organic Compound (VOC) Concentrations in Groundwater in the Eagle River Watershed Valley-Fill Aquifer, Eagle County, North-Central Colorado, 2006-2007

    Science.gov (United States)

    Rupert, Michael G.; Plummer, Niel

    2009-01-01

    This raster data set delineates the predicted probability of elevated volatile organic compound (VOC) concentrations in groundwater in the Eagle River watershed valley-fill aquifer, Eagle County, North-Central Colorado, 2006-2007. This data set was developed by a cooperative project between the U.S. Geological Survey, Eagle County, the Eagle River Water and Sanitation District, the Town of Eagle, the Town of Gypsum, and the Upper Eagle Regional Water Authority. This project was designed to evaluate potential land-development effects on groundwater and surface-water resources so that informed land-use and water management decisions can be made. This groundwater probability map and its associated probability maps was developed as follows: (1) A point data set of wells with groundwater quality and groundwater age data was overlaid with thematic layers of anthropogenic (related to human activities) and hydrogeologic data by using a geographic information system to assign each well values for depth to groundwater, distance to major streams and canals, distance to gypsum beds, precipitation, soils, and well depth. These data then were downloaded to a statistical software package for analysis by logistic regression. (2) Statistical models predicting the probability of elevated nitrate concentrations, the probability of unmixed young water (using chlorofluorocarbon-11 concentrations and tritium activities), and the probability of elevated volatile organic compound concentrations were developed using logistic regression techniques. (3) The statistical models were entered into a GIS and the probability map was constructed.

  20. Probability of Elevated Nitrate Concentrations in Groundwater in the Eagle River Watershed Valley-Fill Aquifer, Eagle County, North-Central Colorado, 2006-2007

    Science.gov (United States)

    Rupert, Michael G.; Plummer, Niel

    2009-01-01

    This raster data set delineates the predicted probability of elevated nitrate concentrations in groundwater in the Eagle River watershed valley-fill aquifer, Eagle County, North-Central Colorado, 2006-2007. This data set was developed by a cooperative project between the U.S. Geological Survey, Eagle County, the Eagle River Water and Sanitation District, the Town of Eagle, the Town of Gypsum, and the Upper Eagle Regional Water Authority. This project was designed to evaluate potential land-development effects on groundwater and surface-water resources so that informed land-use and water management decisions can be made. This groundwater probability map and its associated probability maps was developed as follows: (1) A point data set of wells with groundwater quality and groundwater age data was overlaid with thematic layers of anthropogenic (related to human activities) and hydrogeologic data by using a geographic information system to assign each well values for depth to groundwater, distance to major streams and canals, distance to gypsum beds, precipitation, soils, and well depth. These data then were downloaded to a statistical software package for analysis by logistic regression. (2) Statistical models predicting the probability of elevated nitrate concentrations, the probability of unmixed young water (using chlorofluorocarbon-11 concentrations and tritium activities), and the probability of elevated volatile organic compound concentrations were developed using logistic regression techniques. (3) The statistical models were entered into a GIS and the probability map was constructed.

  1. Simulation of the interaction of karstic lakes Magnolia and Brooklyn with the upper Floridan Aquifer, southwestern Clay County, Florida

    Science.gov (United States)

    Merritt, M.L.

    2001-01-01

    The stage of Lake Brooklyn, in southwestern Clay County, Florida, has varied over a range of 27 feet since measurements by the U.S. Geological Survey began in July 1957. The large stage changes have been attributed to the relation between highly transient surface-water inflow to the lake and subsurface conduits of karstic origin that permit a high rate of leakage from the lake to the Upper Floridan aquifer. After the most recent and severe stage decline (1990-1994), the U.S. Geological Survey began a study that entailed the use of numerical ground-water flow models to simulate the interaction of the lake with the Upper Floridan aquifer and the large fluctuations of stage that were a part of that process. A package (set of computer programs) designed to represent lake/aquifer interaction in the U.S. Geological Survey Modular Finite-Difference Ground-Water Flow Model (MODFLOW-96) and the Three-Dimensional Method-of-Characteristics Solute-Transport Model (MOC3D) simulators was prepared as part of this study, and a demonstration of its capability was a primary objective of the study. (Although the official names are Brooklyn Lake and Magnolia Lake (Florida Geographic Names), in this report the local names, Lake Brooklyn and Lake Magnolia, are used.) In the simulator of lake/aquifer interaction used in this investigation, the stage of each lake in a simulation is updated in successive time steps by a budget process that takes into account ground-water seepage, precipitation upon and evaporation from the lake surface, stream inflows and outflows, overland runoff inflows, and augmentation or depletion by artificial means. The simulator was given the capability to simulate both the division of a lake into separate pools as lake stage falls and the coalescence of several pools into a single lake as the stage rises. This representational capability was required to simulate Lake Brooklyn, which can divide into as many as 10 separate pools at sufficiently low stage. In the

  2. Age dating ground water by use of chlorofluorocarbons (CCl3F and CCl2F2), and distribution of chlorofluorocarbons in the unsaturated zone, Snake River Plain aquifer, Idaho National Engineering Laboratory, Idaho

    International Nuclear Information System (INIS)

    Busenberg, E.; Weeks, E.P.; Plummer, L.N.; Bartholomay, R.C.

    1993-04-01

    Detectable concentrations of chlorofluorocarbons (CFC's) were observed in ground water and unsaturated-zone air at the Idaho National Engineering Laboratory (INEL) and vicinity. The recharge ages of waters were determined to be from 4 to more than 50 years on the basis of CFC concentrations and other environmental data; most ground waters have ages of 14 to 30 years. These results indicate that young ground water was added at various locations to the older regional ground water (greater than 50 years) within and outside the INEL boundaries. The wells drilled into the Snake River Plain aquifer at INEL sampled mainly this local recharge. The Big Lost River, Birch Creek, the Little Lost River, and the Mud Lake-Terreton area appear to be major sources of recharge of the Snake River Plain aquifer at INEL. An average recharge temperature of 9.7±1.3 degrees C (degrees Celsius) was calculated from dissolved nitrogen and argon concentrations in the ground waters, a temperature that is similar to the mean annual soil temperature of 9 degrees C measured at INEL. This similarity indicates that the aquifer was recharged at INEL and not at higher elevations that would have cooler soil temperatures than INEL. Soil-gas concentrations at Test Area North (TAN) are explained by diffusion theory

  3. Evaluation of Restoration and Flow Interactions on River Structure and Function: Channel Widening of the Thur River, Switzerland

    Directory of Open Access Journals (Sweden)

    Eduardo J. Martín

    2018-04-01

    Full Text Available Removal of lateral constraints to restore rivers has become increasingly common in river resource management, but little is known how the interaction of de-channelization with flow influences ecosystem structure and function. We evaluated the ecosystem effects of river widening to improve sediment relations in the Thur River, Switzerland, 12 years after implementation. We tested if restored and non-restored reaches differed in water physico-chemistry, hyporheic function, primary production, and macroinvertebrate density and composition in relation to the flow regime. Our results showed that (i spatio-temporal variation in sediment respiration and macroinvertebrate taxonomic richness were driven by interactions between restoration and flow; (ii riverbed conditions including substrate size, organic matter content, and groundwater–surface water exchange changed due to restoration, but (iii physico-chemistry, hydraulic conditions, and primary production were not altered by restoration. Importantly, our study revealed that abiotic conditions, except channel morphology, changed only marginally, whereas other ecosystem attributes responded markedly to changes in flow-restoration interactions. These results highlight integrating a more holistic ecosystem perspective in the design and monitoring of restoration projects such as river widening in resource management, preferably in relation to flow-sediment regimes and interactions with the biotic components of the ecosystem.

  4. A Novel Analytical Solution for Estimating Aquifer Properties and Predicting Stream Depletion Rates by Pumping from a Horizontally Anisotropic Aquifer

    Science.gov (United States)

    Huang, Y.; Zhan, H.; Knappett, P.

    2017-12-01

    Past studies modeling stream-aquifer interactions commonly account for vertical anisotropy, but rarely address horizontal anisotropy, which does exist in certain geological settings. Horizontal anisotropy is impacted by sediment deposition rates, orientation of sediment particles and orientations of fractures etc. We hypothesize that horizontal anisotropy controls the volume of recharge a pumped aquifer captures from the river. To test this hypothesis, a new mathematical model was developed to describe the distribution of drawdown from stream-bank pumping with a well screened across a horizontally anisotropic, confined aquifer, laterally bounded by a river. This new model was used to determine four aquifer parameters including the magnitude and directions of major and minor principal transmissivities and storativity based on the observed drawdown-time curves within a minimum of three non-collinear observation wells. By comparing the aquifer parameters values estimated from drawdown data generated known values, the discrepancies of the major and minor transmissivities, horizontal anisotropy ratio, storativity and the direction of major transmissivity were 13.1, 8.8, 4, 0 and managers to exploit groundwater resource reasonably while protecting stream ecosystem.

  5. CROSS-CORRELATION MODELLING OF SURFACE WATER – GROUNDWATER INTERACTION USING THE EXCEL SPREADSHEET APPLICATION

    Directory of Open Access Journals (Sweden)

    Kristijan Posavec

    2017-01-01

    Full Text Available Modelling responses of groundwater levels in aquifer systems, which occur as a reaction to changes in aquifer system boundary conditions such as river or stream stages, is commonly being studied using statistical methods, namely correlation, cross-correlation and regression methods. Although correlation and regression analysis tools are readily available in Microsoft Excel, a widely applied spreadsheet industry standard, the cross-correlation analysis tool is missing. As a part of research of groundwater pressure propagation into alluvial aquifer systems of the Sava and Drava/Danube River catchments following river stages rise, focused on estimating groundwater pressure travel times in aquifers, an Excel spreadsheet data analysis application for cross-correlation modelling has been designed and used in modelling surface water – groundwater interaction. Examples of fi eld data from the Zagreb aquifer system and the Kopački rit Nature Park aquifer system are used to illustrate the usefulness of the cross-correlation application.

  6. Remediation of a marine shore tailings deposit and the importance of water-rock interaction on element cycling in the coastal aquifer.

    Science.gov (United States)

    Dold, Bernhard; Diaby, Nouhou; Spangenberg, Jorge E

    2011-06-01

    We present the study of the geochemical processes associated with the first successful remediation of a marine shore tailings deposit in a coastal desert environment (Bahía de Ite, in the Atacama Desert of Peru). The remediation approach implemented a wetland on top of the oxidized tailings. The site is characterized by a high hydraulic gradient produced by agricultural irrigation on upstream gravel terraces that pushed river water (∼500 mg/L SO(4)) toward the sea and through the tailings deposit. The geochemical and isotopic (δ(2)H(water) and δ(18)O(water), δ(34)S(sulfate), δ(18)O(sulfate)) approach applied here revealed that evaporite horizons (anhydrite and halite) in the gravel terraces are the source of increased concentrations of SO(4), Cl, and Na up to ∼1500 mg/L in the springs at the base of the gravel terraces. Deeper groundwater interacting with underlying marine sequences increased the concentrations of SO(4), Cl, and Na up to 6000 mg/L and increased the alkalinity up to 923 mg/L CaCO(3) eq. in the coastal aquifer. These waters infiltrated into the tailings deposit at the shelf-tailings interface. Nonremediated tailings had a low-pH oxidation zone (pH 1-4) with significant accumulations of efflorescent salts (10-20 cm thick) at the surface because of upward capillary transport of metal cations in the arid climate. Remediated tailings were characterized by neutral pH and reducing conditions (pH ∼7, Eh ∼100 mV). As a result, most bivalent metals such as Cu, Zn, and Ni had very low concentrations (around 0.01 mg/L or below detection limit) because of reduction and sorption processes. In contrast, these reducing conditions increased the mobility of iron from two sources in this system: (1) The originally Fe(III)-rich oxidation zone, where Fe(III) was reduced during the remediation process and formed an Fe(II) plume, and (2) reductive dissolution of Fe(III) oxides present in the original shelf lithology formed an Fe-Mn plume at 10-m depth. These

  7. Uranium series geochemistry in aquifers: quantification of transport mechanisms of uranium and daughter products: the chalk aquifer (Champagne, France)

    International Nuclear Information System (INIS)

    Hubert, A.

    2005-09-01

    With the increase of contaminant flux of radionuclides in surface environment (soil, river, aquifer...), there is a need to understand and model the processes that control the distribution of uranium and its daughter products during transport within aquifers. We have used U-series disequilibria as an analogue for the transport of uranium and its daughter products in aquifer to understand such mechanisms. The measurements of uranium ( 234 U et 238 U), thorium ( 230 Th et 232 Th), 226 Ra and 222 Rn isotopes in the solid and liquid phases of the chalk aquifer in Champagne (East of France) allows us to understand the processes responsible for fractionation within the uranium decay chain. Fractionations are induced by physical and chemical properties of the elements (leaching, adsorption) but also by radioactive properties (recoil effect during α-decay). For the first time a comprehensive sampling of the solid phase has been performed, allowing quantifying mechanisms responsible for the long term evolution of the aquifer. A non steady state 1D model has been developed which takes into account leaching, adsorption processes as well as radioactive filiation and α-recoil effect. Retardation coefficients have been calculated for uranium, thorium and radium. The aquifer is characterised by a double porosity, and the contribution of fracture and matrix porosity on the water/rock interaction processes has been estimated. (author)

  8. Straddle-packer determination of the vertical distribution of hydraulic properties in the Snake River Plain Aquifer at well USGS-44, Idaho Chemical Processing Plant, INEL

    International Nuclear Information System (INIS)

    Monks, J.I.

    1994-01-01

    Many of the monitor wells that penetrate the upper portion of the Snake River Plain aquifer at the Idaho National Engineering Laboratory (INEL) are open over large intervals that include multiple water-bearing zones. Most of these wells are equipped with dedicated submersible pumps. Water of varying quality from different water-bearing zones is mixed within the wells. The hydrologic properties of individual water bearing zones are difficult to determine. Water quality and water-level data on organic, heavy metal, and radioactive contaminants have been collected, reported, and interpreted from these monitor wells for more than forty years. The problems associated with well completions over large intervals through multiple water-bearing zones raise significant questions about the data. A straddle-packer system was developed and applied at the INEL site to investigate the monitor well network. The straddle-packer system, hydraulic testing methods, data analysis procedures, and testing results are described in this report. The straddle-packer system and the straddle-packer testing and data evaluation procedures can be improved for future testing at the INEL site. Recommended improvements to the straddle-packer system are: (1) improved transducer pressure sensing systems, (2) faster opening riser valve, and (3) an in-line flowmeter in the riser pipe. Testing and data evaluation recommended improvements are: (1) simultaneous valve opening during slug tests, (2) analysis of the ratio of the times for head change and recovery to occur, (3) constant-drawdown tests of high transmissivity intervals, (4) multiple-well aquifer tests, and (5) long term head monitoring

  9. A novel analytical solution for estimating aquifer properties within a horizontally anisotropic aquifer bounded by a stream

    Science.gov (United States)

    Huang, Yibin; Zhan, Hongbin; Knappett, Peter S. K.

    2018-04-01

    Past studies modeling stream-aquifer interaction commonly account for vertical anisotropy in hydraulic conductivity, but rarely address horizontal anisotropy, which may exist in certain sedimentary environments. If present, horizontal anisotropy will greatly impact stream depletion and the amount of recharge a pumped aquifer captures from the river. This scenario requires a different and somewhat more sophisticated mathematical approach to model and interpret pumping test results than previous models used to describe captured recharge from rivers. In this study, a new mathematical model is developed to describe the spatiotemporal distribution of drawdown from stream-bank pumping with a well screened across a horizontally anisotropic, confined aquifer, laterally bounded by a river. This new model is used to estimate four aquifer parameters including the magnitude and directions of major and minor principal transmissivities and storativity based on the observed drawdown-time curves within a minimum of three non-collinear observation wells. In order to approve the efficacy of the new model, a MATLAB script file is programmed to conduct a four-parameter inversion to estimate the four parameters of concern. By comparing the results of analytical and numerical inversions, the accuracy of estimated results from both inversions is acceptable, but the MATLAB program sometimes becomes problematic because of the difficulty of separating the local minima from the global minima. It appears that the new analytical model of this study is applicable and robust in estimating parameter values for a horizontally anisotropic aquifer laterally bounded by a stream. Besides that, the new model calculates stream depletion rate as a function of stream-bank pumping. Unique to horizontally anisotropic and homogeneous aquifers, the stream depletion rate at any given pumping rate depends closely on the horizontal anisotropy ratio and the direction of the principle transmissivities relative to

  10. Transboundary water resources management and livelihoods: interactions in the Senegal river

    Science.gov (United States)

    Bruckmann, Laurent; Beltrando, Gérard

    2016-04-01

    In Sub-Saharan Africa, 90 % of wetlands provide ecosystem services to societies, especially for agriculture and fishing. However, tropical rivers are increasingly regulated to provide hydroelectricity and irrigated agriculture. Modifications of flows create new hydrological conditions that affect floodplains ecology and peoples' livelihoods. In the Senegal river valley, large dams were built during the 1980's to secure water resources after a decade of water scarcity in the 1970's: Manantali in the upper basin with a reservoir of 12km3 and Diama close to estuary to avoid saltwater intrusion during dry season. Senegal river water resources are known under the supervision of Senegal River Basin Development Organization (OMVS), which defines water allocation between different goals (electricity, irrigation, traditional activities). This study, based on the concept of socio-hydrology, analyses socio-ecological changes following thirty years of dam management. The work enlightens adaptation mechanisms of livelihoods from people living along the river floodplain and feedback on water ressources. The study uses a mixed method approach, combining hydrological analyses, literature review and data collection from surveys on stakeholders and key informants level in the middle Senegal valley. Our results suggest that in all the Senegal river valley, socio-ecological changes are driven by new hydrological conditions. If dam management benefit for peoples with electrification and development of an irrigated agriculture, it has also emphasized the floodplain degradation. Flooded area has decline and are more irregular, causing an erosion of floodplain supporting services (traditional activities as fishing, grazing and flood-recession agriculture). These conditions reduce peoples' livelihood possibilities and irrigation is the only regular activity. As a feedback, irrigated agriculture increases withdrawals in the river and, recently, in aquifers posing a new uncertainty on water

  11. Carbonate aquifers

    Science.gov (United States)

    Cunningham, Kevin J.; Sukop, Michael; Curran, H. Allen

    2012-01-01

    Only limited hydrogeological research has been conducted using ichnology in carbonate aquifer characterization. Regardless, important applications of ichnology to carbonate aquifer characterization include its use to distinguish and delineate depositional cycles, correlate mappable biogenically altered surfaces, identify zones of preferential groundwater flow and paleogroundwater flow, and better understand the origin of ichnofabric-related karst features. Three case studies, which include Pleistocene carbonate rocks of the Biscayne aquifer in southern Florida and Cretaceous carbonate strata of the Edwards–Trinity aquifer system in central Texas, demonstrate that (1) there can be a strong relation between ichnofabrics and groundwater flow in carbonate aquifers and (2) ichnology can offer a useful methodology for carbonate aquifer characterization. In these examples, zones of extremely permeable, ichnofabric-related macroporosity are mappable stratiform geobodies and as such can be represented in groundwater flow and transport simulations.

  12. Actinide-soil interactions in waste management at the Savannah River Plant

    International Nuclear Information System (INIS)

    Holcomb, H.P.; Horton, J.H.; Wilhite, E.L.

    1976-01-01

    Three aspects of the transuranium (TRU) nuclide-soil interaction were studied in connection with Savannah River Plant (SRP) burial ground operations. Results of the studies are reported as three separate parts of this report

  13. Characteristics of streams and aquifers and processes affecting the salinity of water in the upper Colorado River basin, Texas

    Science.gov (United States)

    Slade, R.M.; Buszka, P.M.

    1994-01-01

    The upper Colorado River and some of its tributaries between Lake J.B. Thomas and O.H. Ivie Reservoir contain saline water (defined as water having dissolved-solids concentrations greater than 1,000 milligrams per liter). Dissolved-solids loads at nine streamflow water-quality stations increased from 1986 to 1988. The largest increases were in Beals Creek and in the Colorado River downstream from Beals Creek as a result of outflow of saline water from Natural Dam Salt Lake. The outflow contained 654,000 tons of dissolved solids and had a mean dissolved-solids concentration of 7,900 milligrams per liter. This amount represents about 51 percent of the dissolved-solids load to E.V. Spence Reservoir during 1986-88.

  14. Characterizing the interaction of groundwater and surface water in the karst aquifer of Fangshan, Beijing (China)

    Science.gov (United States)

    Chu, Haibo; Wei, Jiahua; Wang, Rong; Xin, Baodong

    2017-03-01

    Correct understanding of groundwater/surface-water (GW-SW) interaction in karst systems is of greatest importance for managing the water resources. A typical karst region, Fangshan in northern China, was selected as a case study. Groundwater levels and hydrochemistry analyses, together with isotope data based on hydrogeological field investigations, were used to assess the GW-SW interaction. Chemistry data reveal that water type and the concentration of cations in the groundwater are consistent with those of the surface water. Stable isotope ratios of all samples are close to the local meteoric water line, and the 3H concentrations of surface water and groundwater samples are close to that of rainfall, so isotopes also confirm that karst groundwater is recharged by rainfall. Cross-correlation analysis reveals that rainfall leads to a rise in groundwater level with a lag time of 2 months and groundwater exploitation leads to a fall within 1 month. Spectral analysis also reveals that groundwater level, groundwater exploitation and rainfall have significantly similar response periods, indicating their possible inter-relationship. Furthermore, a multiple nonlinear regression model indicates that groundwater level can be negatively correlated with groundwater exploitation, and positively correlated with rainfall. The overall results revealed that groundwater level has a close correlation with groundwater exploitation and rainfall, and they are indicative of a close hydraulic connection and interaction between surface water and groundwater in this karst system.

  15. Studying groundwater and surface water interactions using airborne remote sensing in Heihe River basin, northwest China

    Science.gov (United States)

    Liu, C.; Liu, J.; Hu, Y.; Zheng, C.

    2015-05-01

    Managing surface water and groundwater as a unified system is important for water resource exploitation and aquatic ecosystem conservation. The unified approach to water management needs accurate characterization of surface water and groundwater interactions. Temperature is a natural tracer for identifying surface water and groundwater interactions, and the use of remote sensing techniques facilitates basin-scale temperature measurement. This study focuses on the Heihe River basin, the second largest inland river basin in the arid and semi-arid northwest of China where surface water and groundwater undergoes dynamic exchanges. The spatially continuous river-surface temperature of the midstream section of the Heihe River was obtained by using an airborne pushbroom hyperspectral thermal sensor system. By using the hot spot analysis toolkit in the ArcGIS software, abnormally cold water zones were identified as indicators of the spatial pattern of groundwater discharge to the river.

  16. Studying groundwater and surface water interactions using airborne remote sensing in Heihe River basin, northwest China

    Directory of Open Access Journals (Sweden)

    C. Liu

    2015-05-01

    Full Text Available Managing surface water and groundwater as a unified system is important for water resource exploitation and aquatic ecosystem conservation. The unified approach to water management needs accurate characterization of surface water and groundwater interactions. Temperature is a natural tracer for identifying surface water and groundwater interactions, and the use of remote sensing techniques facilitates basin-scale temperature measurement. This study focuses on the Heihe River basin, the second largest inland river basin in the arid and semi-arid northwest of China where surface water and groundwater undergoes dynamic exchanges. The spatially continuous river-surface temperature of the midstream section of the Heihe River was obtained by using an airborne pushbroom hyperspectral thermal sensor system. By using the hot spot analysis toolkit in the ArcGIS software, abnormally cold water zones were identified as indicators of the spatial pattern of groundwater discharge to the river.

  17. Interaction between shallow and deep aquifers in the Tivoli Plain (Central Italy) enhanced by groundwater extraction: A multi-isotope approach and geochemical modeling

    International Nuclear Information System (INIS)

    Carucci, Valentina; Petitta, Marco; Aravena, Ramon

    2012-01-01

    In the Tivoli Plain (Rome, Central Italy) the interaction between shallow and deep groundwater flow systems enhanced by groundwater extraction has been investigated using isotopic and chemical tracers. A conceptual model of the groundwater flowpaths has been developed and verified by geochemical modeling. A combined hydrogeochemical and isotopic investigation using ion relationships such as DIC/Cl − , Ca/(Ca + Mg)/SO 4 /(SO 4 + HCO 3 ), and environmental isotopes (δ 18 O, δ 2 H, 87 Sr/ 86 Sr, δ 34 S and δ 13 C) was carried out in order to determine the sources of recharge of the aquifer, the origin of solutes and the mixing processes in groundwater of Tivoli Plain. Multivariate statistical methods such as principal component analysis and Cluster analyses have confirmed the existence of different geochemical facies and the role of mixing in the chemical composition of the groundwater. Results indicate that the hydrochemistry of groundwater is characterized by mixing between end-members coming directly from carbonate recharge areas and to groundwater circulating in a deeply buried Meso-Cenozoic carbonate sequence. The travertine aquifer is fed by both flow systems, but a local contribution by direct input in the Plain has also been recognized. The stable isotope data ( 18 O, 2 H, 13 C and 34 S) supports the flow system conceptual model inferred from the geochemical data and represents key data to quantify the geochemical mixing in the different groundwaters of the Plain. The results of numerical modeling (PHREEQC) are consistent with the flowpaths derived from the hydrogeochemical conceptual model. The inverse models performed generated the main geochemical processes occurring in the groundwater flow system, which also included mixing. Geochemical and isotope modeling demonstrate an increasing influence of groundwater from the deeply buried aquifer in the travertine aquifer, enhanced by lowering of the travertine aquifer water table due to quarry pumping.

  18. Towards improved instrumentation for assessing river-groundwater interactions in a restored river corridor

    Directory of Open Access Journals (Sweden)

    P. Schneider

    2011-08-01

    Full Text Available River restoration projects have been launched over the last two decades to improve the ecological status and water quality of regulated rivers. As most restored rivers are not monitored at all, it is difficult to predict consequences of restoration projects or analyze why restorations fail or are successful. It is thus necessary to implement efficient field assessment strategies, for example by employing sensor networks that continuously measure physical parameters at high spatial and temporal resolution. This paper focuses on the design and implementation of an instrumentation strategy for monitoring changes in bank filtration, hydrological connectivity, groundwater travel time and quality due to river restoration. We specifically designed and instrumented a network of monitoring wells at the Thur River (NE Switzerland, which is partly restored and has been mainly channelized for more than 100 years. Our results show that bank filtration – especially in a restored section with alternating riverbed morphology – is variable in time and space. Consequently, our monitoring network has been adapted in response to that variability. Although not available at our test site, we consider long-term measurements – ideally initiated before and continued after restoration – as a fundamental step towards predicting consequences of river restoration for groundwater quality. As a result, process-based models could be adapted and evaluated using these types of high-resolution data sets.

  19. Quantifying wetland–aquifer interactions in a humid subtropical climate region: An integrated approach

    Science.gov (United States)

    Mendoza-Sanchez, Itza; Phanikumar, Mantha S.; Niu, Jie; Masoner, Jason R.; Cozzarelli, Isabelle M.; McGuire, Jennifer T.

    2013-01-01

    Wetlands are widely recognized as sentinels of global climate change. Long-term monitoring data combined with process-based modeling has the potential to shed light on key processes and how they change over time. This paper reports the development and application of a simple water balance model based on long-term climate, soil, vegetation and hydrological dynamics to quantify groundwater–surface water (GW–SW) interactions at the Norman landfill research site in Oklahoma, USA. Our integrated approach involved model evaluation by means of the following independent measurements: (a) groundwater inflow calculation using stable isotopes of oxygen and hydrogen (16O, 18O, 1H, 2H); (b) seepage flux measurements in the wetland hyporheic sediment; and (c) pan evaporation measurements on land and in the wetland. The integrated approach was useful for identifying the dominant hydrological processes at the site, including recharge and subsurface flows. Simulated recharge compared well with estimates obtained using isotope methods from previous studies and allowed us to identify specific annual signatures of this important process during the period of study (1997–2007). Similarly, observations of groundwater inflow and outflow rates to and from the wetland using seepage meters and isotope methods were found to be in good agreement with simulation results. Results indicate that subsurface flow components in the system are seasonal and readily respond to rainfall events. The wetland water balance is dominated by local groundwater inputs and regional groundwater flow contributes little to the overall water balance.

  20. Interactions between mobilized radionuclides and secondary phases in final repository-relevant formation aquifers. Final report; Wechselwirkung mobilisierter Radionuklide mit sekundaeren Phasen in endlagerrelevanten Formationswaessern. Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Curtius, H.; Kaiser, G.; Paparigas, Z.; Hansen, B.; Neumann, A.; Klinkenberg, M.; Mueller, E.; Bruecher, H.; Bosbach, D.

    2010-10-15

    The report on interactions between mobilized radionuclides and secondary phases in final repository-relevant formation aquifers covers the following issues: scope of study, leaching experiments, secondary phases, incorporation and sorption studies, summary and prospects. The results show that the investigated spent fuels dissolve instantaneously in contact with the repository-relevant aquifers in presence of iron ions. For the elements Cs and Sr no re-immobilization was observed. These elements have to be considered as mobile species in the radionuclide source term. The secondary phases due to corrosion processes are radionuclide sinks, i.e. actinides are re-immobilized, the retention mechanisms were clarified. The studies with irradiated nuclear fuel show that the uranium/silicon containing phases effect the molar solubility of actinides.

  1. Numerical Study of Groundwater Flow and Salinity Distribution Cycling Controlled by Seawater/Freshwater Interaction in Karst Aquifer Using SEAWAT

    Science.gov (United States)

    Xu, Z.; Hu, B.

    2017-12-01

    The interest to predict seawater intrusion and salinity distribution in Woodville Karst Plain (WKP) has increased due to the huge challenge on quality of drinkable water and serious environmental problems. Seawater intrudes into the conduit system from submarine karst caves at Spring Creek Spring due to density difference and sea level rising, nowadays the low salinity has been detected at Wakulla Spring which is 18 km from coastal line. The groundwater discharge at two major springs and salinity distribution in this area is controlled by the seawater/freshwater interaction under different rainfall conditions: during low rainfall periods, seawater flow into the submarine spring through karst windows, then the salinity rising at the submarine spring leads to seawater further intrudes into conduit system; during high rainfall periods, seawater is pushed out by fresh water discharge at submarine spring. The previous numerical studies of WKP mainly focused on the density independent transport modeling and seawater/freshwater discharge at major karst springs, in this study, a SEAWAT model has been developed to fully investigate the salinity distribution in the WKP under repeating phases of low rainfall and high rainfall periods, the conduit system was simulated as porous media with high conductivity and porosity. The precipitation, salinity and discharge at springs were used to calibrate the model. The results showed that the salinity distribution in porous media and conduit system is controlled by the rainfall change, in general, the salinity distribution inland under low rainfall conditions is much higher and wider than the high rainfall conditions. The results propose a prediction on the environmental problem caused by seawater intrusion in karst coastal aquifer, in addition, provide a visual and scientific basis for future groundwater remediation.

  2. Water-Rock Interactions in the Peridotite Aquifer of the Oman-UAE Ophiolite: Strontium Isotopic Ratio and Geochemical Evolution of Groundwater

    Science.gov (United States)

    Bompard, Nicolas; Matter, Juerg; Teagle, Damon

    2016-04-01

    The peridotite aquifer in Wadi Tayin, Sultanate of Oman, is a perfect example of natural carbonation of ultramafic rocks. In situ mineral carbonation is considered the most safest and permanent option of CO2 Capture and Sequestration (CCS). However, the process itself is yet to be characterised and a better understanding of the mechanisms involved in natural mineral carbonation is needed before geo-engineering it. We used the 87Sr/86Sr system to follow the water-rock interactions along the groundwater flowpath in the peridotite aquifer and to determine the sources of divalent cations (Mg2+, Ca2+) required for mineral carbonation. The Sr-isotope data of groundwater show that the aquifer rocks are the main source for divalent cations (Mg2+, Ca2+ and Sr2+) and secondary carbonates are their main sink. The groundwater 87Sr/86Sr ratio evolves with its pH: from 87Sr/86Sr = 0.7087 (n=3) to 0.7082 (n=8) between pH 7 and 8, and from 0.7086 (n=6) at pH 9 to 0.07075 (n=9) at pH 11. This evolution seems to support a two-step model for the water-rock interactions in the peridotite aquifer. From pH 7 to 8, secondary Ca-carbonate precipitation buffers the pH rise resulting from peridotite serpentinisation. From pH 9 to 11, peridotite serpentinisation drives the pH to alkaline condition. The change from a Mg-rich to a Ca-rich groundwater at pH 9 seems to confirm the two-step model.

  3. Sele coastal plain flood risk due to wave storm and river flow interaction

    Science.gov (United States)

    Benassai, Guido; Aucelli, Pietro; Di Paola, Gianluigi; Della Morte, Renata; Cozzolino, Luca; Rizzo, Angela

    2016-04-01

    Wind waves, elevated water levels and river discharge can cause flooding in low-lying coastal areas, where the water level is the interaction between wave storm elevated water levels and river flow interaction. The factors driving the potential flood risk include weather conditions, river water stage and storm surge. These data are required to obtain inputs to run the hydrological model used to evaluate the water surface level during ordinary and extreme events regarding both the fluvial overflow and storm surge at the river mouth. In this paper we studied the interaction between the sea level variation and the river hydraulics in order to assess the location of the river floods in the Sele coastal plain. The wave data were acquired from the wave buoy of Ponza, while the water level data needed to assess the sea level variation were recorded by the tide gauge of Salerno. The water stages, river discharges and rating curves for Sele river were provided by Italian Hydrographic Service (Servizio Idrografico e Mareografico Nazionale, SIMN).We used the dataset of Albanella station (40°29'34.30"N, 15°00'44.30"E), located around 7 km from the river mouth. The extreme river discharges were evaluated through the Weibull equation, which were associated with their return period (TR). The steady state river water levels were evaluated through HEC-RAS 4.0 model, developed by Hydrologic Engineering Center (HEC) of the United States Army Corps of Engineers Hydrologic Engineering Center (USACE,2006). It is a well-known 1D model that computes water surface elevation (WSE) and velocity at discrete cross-sections by solving continuity, energy and flow resistance (e.g., Manning) equation. Data requirements for HEC-RAS include topographic information in the form of a series of cross-sections, friction parameter in the form of Manning's n values across each cross-section, and flow data including flow rates, flow change locations, and boundary conditions. For a steady state sub

  4. Study of interaction of shallow groundwater and river along the Cisadane and Ciliwung river of Jakarta basin and its management using environmental isotopes

    International Nuclear Information System (INIS)

    Sidauruk, P.; Syafalni; Satrio

    2012-01-01

    The environmental isotopes were employed to study the interaction of shallow groundwater and river along the Cisadane River and Ciliwung River in Jakarta basin. The rapid growth and development of Jakarta and its surrounding cities, coupled with increasing industrial and other business sectors have impacted on the demand of the water supply for the area. These investigations have been conducted to determine the interaction between shallow groundwater and the river. The 14 C results showed that the groundwater samples (above 40 m) which were close to the river influenced the iso-age contour of 14 C, which indicated the contributions of river water. The analysis of stable isotopes 18 O and Deuterium from the river implied that the river water from upstream to downstream was influenced by the mixing of the river water with the human activities in the upstream (the isotopic compositions becoming enriched). Further, the 18 O and Deuterium data revealed that rivers of Cisadane and Ciliwung are contributing to recharge the shallow groundwater in Jakarta, especially in the nearby river bank. In general, the quality of the shallow groundwater along the rivers is good and is suitable as fresh water resource. Due to pollution and declining water table problems in the Jakarta basin, the artificial recharge wells is shown to be a good way out to delineate the problems as indicated by pilot project conducted at Kelurahan Kramat Jati, using infiltration basin method. (author)

  5. Characterizing interactions between surface water and groundwater in the Jialu River basin using major ion chemistry and stable isotopes

    Directory of Open Access Journals (Sweden)

    L. Yang

    2012-11-01

    Full Text Available The Jialu River, a secondary tributary of the Huaihe River, has been severely contaminated from major contaminant sources, such as a number of untreated or lightly treated sewage waste in some cities. Groundwater along the river is not an isolated component of the hydrologic system, but is instead connected with the surface water. This study aims to investigate temporal and spatial variations in water chemistry affected by humans and to characterize the relationships between surface water (e.g. reservoirs, lakes and rivers and groundwater near the river in the shallow Quaternary aquifer. Concentration of Cl in north Zhengzhou City increased prominently due to the discharge of a large amount of domestic water. Nitrate and potassium show maximum concentrations in groundwater in Fugou County. These high levels can be attributed to the use of a large quantity of fertilizer over this region. Most surface water appeared to be continuously recharged from the surrounding groundwater (regional wells based on comparison surface water with groundwater levels, stable-isotopes and major ion signatures. However, the groundwater of a transitional well (location SY3 seemed to be recharged by river water via bank infiltration in September 2010. Fractional contributions of river water to the groundwater were calculated based on isotopic and chemical data using a mass-balance approach. Results show that the groundwater was approximately composed of 60–70% river water. These findings should be useful for a better understanding of hydrogeological processes at the river-aquifer interface and ultimately benefit water management in the future.

  6. Water Quality Interaction with Alkaline Phosphatase in the Ganga River: Implications for River Health.

    Science.gov (United States)

    Yadav, Amita; Pandey, Jitendra

    2017-07-01

    Carbon, nitrogen and phosphorus inputs through atmospheric deposition, surface runoff and point sources were measured in the Ganga River along a gradient of increasing human pressure. Productivity variables (chlorophyll a, gross primary productivity, biogenic silica and autotrophic index) and heterotrophy (respiration, substrate induced respiration, biological oxygen demand and fluorescein diacetate hydrolysis) showed positive relationships with these inputs. Alkaline phosphatase (AP), however, showed an opposite trend. Because AP is negatively influenced by available P, and eutrophy generates a feedback on P fertilization, the study implies that the alkaline phosphatase can be used as a high quality criterion for assessing river health.

  7. Water pollution control in river basin by interactive fuzzy interval multiobjective programming

    Energy Technology Data Exchange (ETDEWEB)

    Chang, N.B.; Chen, H.W. [National Cheng-Kung Univ., Tainan (Taiwan, Province of China). Dept. of Environmental Engineering; Shaw, D.G.; Yang, C.H. [Academia Sinica, Taipei (Taiwan, Province of China). Inst. of Economics

    1997-12-01

    The potential conflict between protection of water quality and economic development by different uses of land within river basins is a common problem in regional planning. Many studies have applied multiobjective decision analysis under uncertainty to problems of this kind. This paper presents the interactive fuzzy interval multiobjective mixed integer programming (IFIMOMIP) model to evaluate optimal strategies of wastewater treatment levels within a river system by considering the uncertainties in decision analysis. The interactive fuzzy interval multiobjective mixed integer programming approach is illustrated in a case study for the evaluation of optimal wastewater treatment strategies for water pollution control in a river basin. In particular, it demonstrates how different types of uncertainty in a water pollution control system can be quantified and combined through the use of interval numbers and membership functions. The results indicate that such an approach is useful for handling system complexity and generating more flexible policies for water quality management in river basins.

  8. Interaction of the sea breeze with a river breeze in an area of complex coastal heating

    Science.gov (United States)

    Zhong, Shiyuan; Takle, Eugene S.; Leone, John M., Jr.

    1991-01-01

    The interaction of the sea-breeze circulation with a river-breeze circulation in an area of complex coastal heating (east coast of Florida) was studied using a 3D finite-element mesoscale model. The model simulations are compared with temperature and wind fields observed on a typical fall day during the Kennedy Space Center Atmospheric Boundary Layer Experiment. The results from numerical experiments designed to isolate the effect of the river breeze indicate that the convergence in the sea-breeze front is suppressed when it passes over the cooler surface of the rivers.

  9. Hydrogeologic controls imposed by mechanical stratigraphy in layered rocks of the Chateauguay River Basin, a U.S.-Canada transborder aquifer

    Science.gov (United States)

    Morin, Roger H.; Godin, Rejean; Nastev, Miroslav; Rouleau, Alain

    2007-01-01

    [1] The Châteauguay River Basin delineates a transborder watershed with roughly half of its surface area located in northern New York State and half in southern Québec Province, Canada. As part of a multidisciplinary study designed to characterize the hydrogeologic properties of this basin, geophysical logs were obtained in 12 wells strategically located to penetrate the four major sedimentary rock formations that constitute the regional aquifers. The layered rocks were classified according to their elastic properties into three primary units: soft sandstone, hard sandstone, and dolostone. Downhole measurements were analyzed to identify fracture patterns associated with each unit and to evaluate their role in controlling groundwater flow. Fracture networks are composed of orthogonal sets of laterally extensive, subhorizontal bedding plane partings and bed-delimited, subvertical joints with spacings that are consistent with rock mechanics principles and stress models. The vertical distribution of transmissive zones is confined to a few select bedding plane fractures, with soft sandstone having the fewest (one per 70-m depth) and hard sandstone the most (five per 70-m depth). Bed-normal permeability is examined using a probabilistic model that considers the lengths of flow paths winding along joints and bedding plane fractures. Soft sandstone has the smallest bed-normal permeability primarily because of its wide, geomechanically undersaturated joint spacing. Results indicate that the three formations have similar values of bulk transmissivity, within roughly an order of magnitude, but that each rock unit has its own unique system of groundwater flow paths that constitute that transmissivity.

  10. Ecological interactions between hatchery summer steelhead and wild Oncorhynchus mykiss in the Willamette River basin, 2014

    Energy Technology Data Exchange (ETDEWEB)

    Harnish, Ryan A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Green, Ethan D. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Vernon, Christopher R. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Mcmichael, Geoffrey A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2014-12-01

    The purpose of this study was to determine the extent to which juvenile hatchery summer steelhead and wild winter steelhead overlap in space and time, to evaluate the extent of residualism among hatchery summer steelhead in the South Santiam River, and to evaluate the potential for negative ecological interactions among hatchery summer steelhead and wild winter steelhead. Because it is not possible to visually discern juvenile winter steelhead from resident rainbow trout, we treated all adipose-intact juvenile O. mykiss as one group that represented juvenile wild winter steelhead. The 2014 study objectives were to 1) estimate the proportion of hatchery summer steelhead that residualized in the South Santiam River in 2014, 2) determine the extent to which hatchery and naturally produced O. mykiss overlapped in space and time in the South Santiam River, and 3) characterize the behavioral interactions between hatchery-origin juvenile summer steelhead and naturally produced O. mykiss. We used a combination of radio telemetry and direct observations (i.e., snorkeling) to determine the potential for negative interactions between hatchery summer and wild winter steelhead juveniles in the South Santiam River. Data collected from these two independent methods indicated that a significant portion of the hatchery summer steelhead released as smolts did not rapidly emigrate from the South Santiam River in 2014. Of the 164 radio-tagged steelhead that volitionally left the hatchery, only 66 (40.2%) were detected outside of the South Santiam River. Forty-four (26.8% of 164) of the radio-tagged hatchery summer steelhead successfully emigrated to Willamette Falls. Thus, the last known location of the majority of the tagged fish (98 of 164 = 59.8%) was in the South Santiam River. Thirty-three of the tagged hatchery steelhead were detected in the South Santiam River during mobile-tracking surveys. Of those, 21 were found to be alive in the South Santiam River over three months after

  11. Inferring Groundwater Age in an Alluvial Aquifer from Tracer Concentrations in the Stream - Little Wind River, Wyoming

    Science.gov (United States)

    Goble, D.; Gardner, W. P.; Naftz, D. L.; Solder, J. E.

    2017-12-01

    We use environmental tracers: CFC's, SF6, and 222Rn measured in stream water to determine volume and mean age of groundwater discharging to the Little Wind River, near Riverton, Wyoming. Samples of 222Rn were collected every 200 m along a 2 km reach, surrounding a known groundwater discharge zone. Nearby groundwater wells, in-stream piezometers and seepage meters were sampled for 222Rn, CFC's and SF6. Tracer concentrations measured in groundwater and in-stream piezometers were used to estimate the mean age of the subsurface system. High resolution 222Rn samples were used to determine the location and volume of groundwater inflow using a model of instream transport that includes radioactive decay and gas exchange with the atmosphere. The age of groundwater entering the stream was then estimated from in-stream measured CFC and SF6 concentrations using a new coupled stream transport and lumped-parameter groundwater age model. Ages derived from in-stream measurements were then compared to the age of subsurface water measured in piezometers, seepage meters, and groundwater wells. We then asses the ability of groundwater age inferred from in-stream samples to provide constraint on the age of the subsurface discharge to the stream. The ability to asses groundwater age from in-stream samples can provide a convenient method to constrain the regional distribution of groundwater circulation rates when groundwater sampling is challenging or wells are not in place.

  12. Effects of coexisting BDE-47 on the migration and biodegradation of BDE-99 in river-based aquifer media recharged with reclaimed water.

    Science.gov (United States)

    Yan, Y; Li, Y; Ma, M; Ma, W; Cheng, X; Xu, K

    2018-02-01

    Two prominent polybrominated diphenyl ether (PBDE) congeners have been included in the persistent organic pollutant list, 2,2',4,4',5-tetrabromodiphenyl ether (BDE-99) and 2,2,4,4'-tetrabromodiphenyl ether (BDE-47), which have been detected in treated municipal wastewater, river water, and sediments in China. A lab-scale column experiment was established to investigate the effects of the competitive sorption of BDE-47 on BDE-99 biodegradation and migration in two types of river-based aquifer soils during groundwater recharge with reclaimed water. Two types of recharge columns were used, filled with either silty clay (SC) or black carbon-amended silty clay (BCA). The decay rate constants of BDE-99 in the BCA and SC systems were 0.186 and 0.13 m -1 in the single-solute system and 0.128 and 0.071 m -1 in the binary-solute system, respectively, showing that the decay of BDE-99 was inhibited by the coexistence of BDE-47. This was particularly evident in the SC system because the higher hydrophobicity of BDE-99 determined the higher affinity and competition for sorption sites onto black carbon. The biodegradation of BDE-99 was suppressed by the coexistence of BDE-47, especially in the SC system. Lesser-brominated congeners (BDE-47 and BDE-28) and higher-brominated congeners (BDE-100, BDE-153, BDE-154, and BDE-183) were generated in the four recharge systems, albeit at different ratios. Bacterial biodiversity was influenced by the presence of BDE-47 in the SC system, while it had no significant effect on the BCA system, because the high sorption capacity of black carbon on the hydrophobic PBDEs effectively reduced their toxicity. The ranking order of the most abundant classes changed markedly due to the coexistence of BDE-47 in both the SC and BCA systems. The ranking order of the most abundant genera changed from Azospira, Methylotenera, Desulfovibrio, Methylibium, and Bradyrhizobium to Halomonas, Hyphomicrobium, Pseudomonas, Methylophaga, and Shewanella, which could

  13. Ozark Aquifer

    Data.gov (United States)

    Kansas Data Access and Support Center — These digital maps contain information on the altitude of the base and top, the extent, and the potentiometric surface of the Ozark aquifer in Kansas. The Ozark...

  14. Depth and temporal variations in water quality of the Snake River Plain aquifer in well USGS-59 near the Idaho Chemical Processing Plant at the Idaho National Engineering and Environmental Laboratory

    International Nuclear Information System (INIS)

    Frederick, D.B.; Johnson, G.S.

    1997-03-01

    In-situ measurements of the specific conductance and temperature of ground water in the Snake River Plain aquifer were collected in observation well USGS-59 near the Idaho Chemical Processing Plant at the Idaho National Engineering and Environmental Laboratory. These parameters were monitored at various depths in the aquifer from October 1994 to August 1995. The specific conductance of ground water in well USGS-59, as measured in the borehole, ranged from about 450 to 900 microS/cm at standard temperature (25 C). The pumping cycle of the production wells at the Idaho Chemical Processing Plant causes changes in borehole circulation patterns, and as a result the specific conductance of ground water at some depths in the well varies by up to 50% over a period of about 14 hours. However, these variations were not observed at all depths, or during each pumping cycle. The temperature of ground water in the well was typically between 12.8 and 13.8 C. The results of this study indicate that temporal variations in specific conductance of the ground water at this location are caused by an external stress on the aquifer--pumping of a production well approximately 4,000 feet away. These variations are believed to result from vertical stratification of water quality in the aquifer and a subsequent change in intrawell flow related to pumping. When sampling techniques that do not induce a stress on the aquifer (i.e., thief sampling) are used, knowledge of external stresses on the system at the time of sampling may aid in the interpretation of geochemical data

  15. Determination of aquifer roof extending under the sea from variable-density flow modelling of groundwater response to tidal loading: case study of the Jahe River Basin, Shandong Province, China

    Science.gov (United States)

    Cheng, Jianmei; Chen, Chongxi; Ji, Menrui

    The main task of studies on salt-water intrusion into coastal confined aquifers is to predict the position of the fresh- salt-water interface, which can be determined from the length of the aquifer roof extending under the sea. Records of groundwater level affected by tides can be used to infer hydrological conditions and determine hydraulic parameters of an aquifer extending under the sea. In this paper, a three-dimensional, variable-density groundwater flow model has been developed to determine the equivalent roof length of an aquifer extending under the sea from the tidal-effected data of groundwater level in the Jahe River Basin, Shandong Province, China. The seaward boundary is obtained by converging hydraulic head fluctuations observed in drill holes with calculated values, and the aquifer parameters in the extending zone are estimated. The impacts of aquifer roof length and aquifer parameters on the fluctuation of tidal groundwater are studied. It is concluded that the length of the aquifer roof extending under the sea should correspond with certain aquifer parameters in the extrapolation zone. Therefore, the seaward boundary determined from tidal-effect information is the equivalent boundary in hydrodynamic characteristics rather than the true boundary of the confined aquifer Les sujets principaux des études d'instrusion saline dans les aquifères confinés en zone côtière sont la prédiction de la position de l'interface entre l'eau salée et l'eau fraîche, qui peut être déterminée à partir de l'extention du toit de l'aquifère sous la mer. Les enregistrements des niveaux des eaux souterraines influencés par les marées peuvent être utilisés pour préciser les conditions hydrologiques et déterminer les paramètres hydrauliques d'un aquifère possédant une extension sous la mer. Dans cet article, un modèle tridimensionnel comprenant des eaux souterraines de densité variable a été développé pour déterminer la longueur équivalente du toit

  16. Investigation of groundwater-streamflow interactions in the Bega alluvial aquifer using tritium and stable isotope ratios

    International Nuclear Information System (INIS)

    Stone, D.J.M.; Thomas, M.; Russell, G.

    2001-01-01

    An isotope hydrology study of the Bega Valley groundwater system has been made. The investigation which focussed on environmental tritium and stable isotope ratios confirms that that the groundwater in the alluvial aquifer of the Bega Valley is sustainable at the current usage rate

  17. Hydrological controls on transient aquifer storage in a karst watershed

    Science.gov (United States)

    Spellman, P.; Martin, J.; Gulley, J. D.

    2017-12-01

    While surface storage of floodwaters is well-known to attenuate flood peaks, transient storage of floodwaters in aquifers is a less recognized mechanism of flood peak attenuation. The hydraulic gradient from aquifer to river controls the magnitude of transient aquifer storage and is ultimately a function of aquifer hydraulic conductivity, and effective porosity. Because bedrock and granular aquifers tend to have lower hydraulic conductivities and porosities, their ability to attenuate flood peaks is generally small. In karst aquifers, however, extensive cave systems create high hydraulic conductivities and porosities that create low antecedent hydraulic gradients between aquifers and rivers. Cave springs can reverse flow during high discharges in rivers, temporarily storing floodwaters in the aquifer thus reducing the magnitude of flood discharge downstream. To date however, very few studies have quantified the magnitude or controls of transient aquifer storage in karst watersheds. We therefore investigate controls on transient aquifer storage by using 10 years of river and groundwater data from the Suwannee River Basin, which flows over the karstic upper Floridan aquifer in north-central Florida. We use multiple linear regression to compare the effects of three hydrological controls on the magnitude of transient aquifer storage: antecedent stage, recharge and slope of hydrograph rise. We show the dominant control on transient aquifer storage is antecedent stage, whereby lower stages result in greater magnitudes of transient aquifer storage. Our results suggest that measures of groundwater levels prior to an event can be useful in determining whether transient aquifer storage will occur and may provide a useful metric for improving predictions of flood magnitudes.

  18. Compilation of geologic, hydrologic, and ground-water flow modeling information for the Spokane Valley-Rathdrum Prairie aquifer, Spokane County, Washington, and Bonner and Kootenai Counties, Idaho

    Science.gov (United States)

    Kahle, Sue C.; Caldwell, Rodney R.; Bartolino, James R.

    2005-01-01

    The U.S. Geological Survey, in cooperation with the Idaho Department of Water Resources and Washington Department of Ecology compiled and described geologic, hydrologic, and ground-water flow modeling information about the Spokane Valley-Rathdrum Prairie (SVRP) aquifer in northern Idaho and northeastern Washington. Descriptions of the hydrogeologic framework, water-budget components, ground- and surface-water interactions, computer flow models, and further data needs are provided. The SVRP aquifer, which covers about 370 square miles including the Rathdrum Prairie, Idaho and the Spokane valley and Hillyard Trough, Washington, was designated a Sole Source Aquifer by the U.S. Environmental Protection Agency in 1978. Continued growth, water management issues, and potential effects on water availability and water quality in the aquifer and in the Spokane and Little Spokane Rivers have illustrated the need to better understand and manage the region's water resources. The SVRP aquifer is composed of sand, gravel, cobbles, and boulders primarily deposited by a series of catastrophic glacial outburst floods from ancient Glacial Lake Missoula. The material deposited in this high-energy environment is coarser-grained than is typical for most basin-fill deposits, resulting in an unusually productive aquifer with well yields as high as 40,000 gallons per minute. In most places, the aquifer is bounded laterally by bedrock composed of granite, metasedimentary rocks, or basalt. The lower boundary of the aquifer is largely unknown except along the margins or in shallower parts of the aquifer where wells have penetrated its entire thickness and reached bedrock or silt and clay deposits. Based on surface geophysics, the thickness of the aquifer is about 500 ft near the Washington-Idaho state line, but more than 600 feet within the Rathdrum Prairie and more than 700 feet in the Hillyard trough based on drilling records. Depth to water in the aquifer is greatest in the northern

  19. Modeling interactions of agriculture and groundwater nitrate contaminants: application of The STICS-Eau-Dyssée coupled models over the Seine River Basin

    Science.gov (United States)

    Tavakoly, A. A.; Habets, F.; Saleh, F.; Yang, Z. L.

    2017-12-01

    Human activities such as the cultivation of N-fixing crops, burning of fossil fuels, discharging of industrial and domestic effluents, and extensive usage of fertilizers have recently accelerated the nitrogen loading to watersheds worldwide. Increasing nitrate concentration in surface water and groundwater is a major concern in watersheds with extensive agricultural activities. Nutrient enrichment is one of the major environmental problems in the French coastal zone. To understand and predict interactions between agriculture, surface water and groundwater nitrate contaminants, this study presents a modeling framework that couples the agronomic STICS model with Eau-Dyssée, a distributed hydrologic modeling system to simulate groundwater-surface water interaction. The coupled system is implemented on the Seine River Basin with an area of 88,000 km2 to compute daily nitrate contaminants. Representing a sophisticated hydrosystem with several aquifers and including the megalopolis of Paris, the Seine River Basin is well-known as one of the most productive agricultural areas in France. The STICS-EauDyssée framework is evaluated for a long-term simulation covering 39 years (1971-2010). Model results show that the simulated nitrate highly depends on the inflow produced by surface and subsurface waters. Daily simulation shows that the model captures the seasonal variation of observations and that the overall long-term simulation of nitrate contaminant is satisfactory at the regional scale.

  20. Variable exchange between a stream and an aquifer in the Rio Grande Project Area

    Science.gov (United States)

    Sheng, Z.; Abudu, S.; Michelsen, A.; King, P.

    2016-12-01

    Both surface water and groundwater in the Rio Grande Project area in southern New Mexico and Far West Texas have been stressed by natural conditions such as droughts and human activities, including urban development and agricultural irrigation. In some area pumping stress in the aquifer becomes so great that it depletes the river flow especially during the irrigation season, typically from March through October. Therefore understanding such relationship between surface water and groundwater becomes more important in regional water resources planning and management. In this area, stream flows are highly regulated by the upstream reservoirs during the irrigation season and greatly influenced by return flows during non-irrigation season. During a drought additional groundwater pumping to supplement surface water shortage further complicates the surface water and groundwater interaction. In this paper the authors will use observation data and results of numerical models (MODFLOW) to characterize and quantify hydrological exchange fluxes between groundwater in the aquifers and surface water as well as impacts of groundwater pumping. The interaction shows a very interesting seasonal variation (irrigation vs. non-irrigation) as well as impact of a drought. Groundwater has been pumped for both municipal supplies and agricultural irrigation, which has imposed stresses toward both stream flows and aquifer storage. The results clearly show that historic groundwater pumping has caused some reaches of the river change from gaining stream to losing stream. Beyond the exchange between surface water and groundwater in the shallow aquifer, groundwater pumping in a deep aquifer could also enhance the exchanges between different aquifers through leaky confining layers. In the earlier history of pumping, pumping from the shallow aquifer is compensated by simple depletion of surface water, while deep aquifer tends to use the aquifer storage. With continued pumping, the cumulative

  1. Quantification of aquifer properties with surface nuclear magnetic resonance in the Platte River valley, central Nebraska, using a novel inversion method

    Science.gov (United States)

    Irons, Trevor P.; Hobza, Christopher M.; Steele, Gregory V.; Abraham, Jared D.; Cannia, James C.; Woodward, Duane D.

    2012-01-01

    Surface nuclear magnetic resonance, a noninvasive geophysical method, measures a signal directly related to the amount of water in the subsurface. This allows for low-cost quantitative estimates of hydraulic parameters. In practice, however, additional factors influence the signal, complicating interpretation. The U.S. Geological Survey, in cooperation with the Central Platte Natural Resources District, evaluated whether hydraulic parameters derived from surface nuclear magnetic resonance data could provide valuable input into groundwater models used for evaluating water-management practices. Two calibration sites in Dawson County, Nebraska, were chosen based on previous detailed hydrogeologic and geophysical investigations. At both sites, surface nuclear magnetic resonance data were collected, and derived parameters were compared with results from four constant-discharge aquifer tests previously conducted at those same sites. Additionally, borehole electromagnetic-induction flowmeter data were analyzed as a less-expensive surrogate for traditional aquifer tests. Building on recent work, a novel surface nuclear magnetic resonance modeling and inversion method was developed that incorporates electrical conductivity and effects due to magnetic-field inhomogeneities, both of which can have a substantial impact on the data. After comparing surface nuclear magnetic resonance inversions at the two calibration sites, the nuclear magnetic-resonance-derived parameters were compared with previously performed aquifer tests in the Central Platte Natural Resources District. This comparison served as a blind test for the developed method. The nuclear magnetic-resonance-derived aquifer parameters were in agreement with results of aquifer tests where the environmental noise allowed data collection and the aquifer test zones overlapped with the surface nuclear magnetic resonance testing. In some cases, the previously performed aquifer tests were not designed fully to characterize

  2. Hydrogeologic framework and groundwater/surface-water interactions of the upper Yakima River Basin, Kittitas County, central Washington

    Science.gov (United States)

    Gendaszek, Andrew S.; Ely, D. Matthew; Hinkle, Stephen R.; Kahle, Sue C.; Welch, Wendy B.

    2014-01-01

    The hydrogeology, hydrology, and geochemistry of groundwater and surface water in the upper (western) 860 square miles of the Yakima River Basin in Kittitas County, Washington, were studied to evaluate the groundwater-flow system, occurrence and availability of groundwater, and the extent of groundwater/surface-water interactions. The study area ranged in altitude from 7,960 feet in its headwaters in the Cascade Range to 1,730 feet at the confluence of the Yakima River with Swauk Creek. A west-to-east precipitation gradient exists in the basin with the western, high-altitude headwaters of the basin receiving more than 100 inches of precipitation per year and the eastern, low-altitude part of the basin receiving about 20 inches of precipitation per year. From the early 20th century onward, reservoirs in the upper part of the basin (for example, Keechelus, Kachess, and Cle Elum Lakes) have been managed to store snowmelt for irrigation in the greater Yakima River Basin. Canals transport water from these reservoirs for irrigation in the study area; additional water use is met through groundwater withdrawals from wells and surface-water withdrawals from streams and rivers. Estimated groundwater use for domestic, commercial, and irrigation purposes is reported for the study area. A complex assemblage of sedimentary, metamorphic, and igneous bedrock underlies the study area. In a structural basin in the southeastern part of the study area, the bedrock is overlain by unconsolidated sediments of glacial and alluvial origin. Rocks and sediments were grouped into six hydrogeologic units based on their lithologic and hydraulic characteristics. A map of their extent was developed from previous geologic mapping and lithostratigraphic information from drillers’ logs. Water flows through interstitial space in unconsolidated sediments, but largely flows through fractures and other sources of secondary porosity in bedrock. Generalized groundwater-flow directions within the

  3. Multilevel groundwater monitoring of hydraulic head and temperature in the eastern Snake River Plain aquifer, Idaho National Laboratory, Idaho, 2009–10

    Science.gov (United States)

    Twining, Brian V.; Fisher, Jason C.

    2012-01-01

    During 2009 and 2010, the U.S. Geological Survey’s Idaho National Laboratory Project Office, in cooperation with the U.S. Department of Energy, collected quarterly, depth-discrete measurements of fluid pressure and temperature in nine boreholes located in the eastern Snake River Plain aquifer. Each borehole was instrumented with a multilevel monitoring system consisting of a series of valved measurement ports, packer bladders, casing segments, and couplers. Multilevel monitoring at the Idaho National Laboratory has been ongoing since 2006. This report summarizes data collected from three multilevel monitoring wells installed during 2009 and 2010 and presents updates to six multilevel monitoring wells. Hydraulic heads (heads) and groundwater temperatures were monitored from 9 multilevel monitoring wells, including 120 hydraulically isolated depth intervals from 448.0 to 1,377.6 feet below land surface. Quarterly head and temperature profiles reveal unique patterns for vertical examination of the aquifer’s complex basalt and sediment stratigraphy, proximity to aquifer recharge and discharge, and groundwater flow. These features contribute to some of the localized variability even though the general profile shape remained consistent over the period of record. Major inflections in the head profiles almost always coincided with low-permeability sediment layers and occasionally thick sequences of dense basalt. However, the presence of a sediment layer or dense basalt layer was insufficient for identifying the location of a major head change within a borehole without knowing the true areal extent and relative transmissivity of the lithologic unit. Temperature profiles for boreholes completed within the Big Lost Trough indicate linear conductive trends; whereas, temperature profiles for boreholes completed within the axial volcanic high indicate mostly convective heat transfer resulting from the vertical movement of groundwater. Additionally, temperature profiles

  4. Defining interactions of in-stream hydrokinetic devices in the Tanana River, Alaska

    Science.gov (United States)

    Johnson, J.; Toniolo, H.; Seitz, A. C.; Schmid, J.; Duvoy, P.

    2012-12-01

    The acceptance, performance, and sustainability of operating in-stream hydrokinetic power generating devices in rivers depends on the impact of the river environment on hydrokinetic infrastructure as well as its impact on the river environment. The Alaska Hydrokinetic Energy Research Center (AHERC) conducts hydrokinetic "impact" and technology studies needed to support a sustainable hydrokinetic industry in Alaska. These include completed and ongoing baseline studies of river hydrodynamic conditions (river stage, discharge, current velocity, power, and turbulence; suspended and bed load sediment transport), ice, fish populations and behavior, surface and subsurface debris flows, and riverbed conditions. Technology and methods studies to minimize the effect of debris flows on deployed turbine system are in-progress to determine their effectiveness at reducing the probability of debris impact, diverting debris and their affect on available river power for conversion to electricity. An anchor point has been placed in the main flow just upstream of Main (Figure 1) to support projects and in preparation for future projects that are being planned to examine hydrokinetic turbine performance including power conversion efficiency, turbine drag and anchor chain loads, wake generation and effects on fish. Baseline fish studies indicate that hydrokinetic devices at the test site will have the most potential interactions with Pacific salmon smolts during their down-migration to the ocean in May and June. At the AHERC test site, the maximum turbulent kinetic energy (TKE) occurs just down stream from the major river bends (e.g., 000 and near the railroad bridge [upper center of the figure]) and over a deep hole at 440 (Figure 1), Minimum TKE occurs between main and 800. River current velocity measurements and simulations of river flow from 000 downstream past the railroad bridge indicate that the most stable current in the river reach is between Main and 800. The stable current

  5. Groundwater Discharges to Rivers in the Western Canadian Oil Sands Region

    Science.gov (United States)

    Ellis, J.; Jasechko, S.

    2016-12-01

    Groundwater discharges into rivers impacts the movement and fate of nutrients and contaminants in the environment. Understanding groundwater-surface water interactions is especially important in the western Canadian oil sands, where groundwater contamination risks are elevated and baseline water chemistry data is lacking, leading to substantial uncertainties about anthropogenic influences on local river quality. High salinity groundwater springs sourced from deep aquifers, comprised of Pleistocene-aged glacial meltwater, are known to discharge into many rivers in the oil sands. Understanding connections between deep aquifers and surficial waterways is important in order to determine natural inputs into these rivers and to assess the potential for injected wastewater or oil extraction fluids to enter surface waters. While these springs have been identified, their spatial distribution along rivers has not been fully characterized. Here we present river chemistry data collected along a number of major river corridors in the Canadian oil sands region. We show that saline groundwater springs vary spatially along the course of these rivers and tend to be concentrated where the rivers incise Devonian- or Cretaceous-aged aquifers along an evaporite dissolution front. Our results suggest that water sourced from Devonian aquifers may travel through bitumen-bearing Cretaceous units and discharge into local rivers, implying a strong groundwater-surface water connection in specialized locations. These findings indicate that oil sands process-affected waters that are injected at depth have the potential to move through these aquifers and reach the rivers at the surface at some time in the future. Groundwater-surface water interactions remain key to understanding the risks oil sands activities pose to aquatic ecosystems and downstream communities.

  6. IAEA KEN 7005 project: Evaluation of Surface and Groundwater Interaction of the Kilimanjaro Aquifer applying Isotope Techniques

    International Nuclear Information System (INIS)

    Opiyo, A.N.E.

    2017-01-01

    Mombasa City is the second largest city in Kenya, has inadequate water supply and experiences a chronic water shortage. Mombasa City and the other areas to its north are supplied with water from the Mzima springs and other systems. Mzima Springs is location in relation to Chyulu Hills and Mt. Kilimanjaro. This study therefore attempts to examine the relationship between Mzima Springs on one hand and Kilimanjaro Aquifer and Chyulu Hills aquifer/springs on the other. The overall objective of this project is to conduct water resources assessment to quantify water in the project area and establish the relationship between surface and groundwater resources in the Mt. Kilimanjaro, Lakes Jipe/Challa, Mzima and Chyulu Hills ecosystem. The Kilimanjaro aquifer includes the volcanic pyroclastic and volcanic alluvium deposits found at the base of Mount Kilimanjaro and extending across the Kenyan-Tanzanian border. Occurrence of groundwater in the surrounding basement plains is limited to faults, fractures and small parts of weathered zones and also to the bottom layers of wide alluvial valleys which are recharged by natural flood spreading. One of the achievement include establishment and equipping of the National Isotope Hydrology Laboratory

  7. Guarani aquifer

    International Nuclear Information System (INIS)

    2007-01-01

    The environmental protection and sustain ability develop project of Guarani Aquifer System is a join work from Argentina, Brazil, Paraguay and Uruguay with a purpose to increase the knowledge resource and propose technical legal and organizational framework for sustainable management between countries.The Universities funds were created as regional universities support in promotion, training and academic research activities related to environmental al social aspects of the Guarani Aquifer System.The aim of the project is the management and protection of the underground waters resources taking advantage and assesment for nowadays and future generations

  8. Strontium isotope geochemistry of groundwater in the central part of the Dakota (Great Plains) aquifer, USA

    International Nuclear Information System (INIS)

    Gosselin, David C.; Edwin Harvey, F.; Frost, Carol; Stotler, Randy; Allen Macfarlane, P.

    2004-01-01

    The Dakota aquifer of the central and eastern Great Plains of the United States is an important source of water for municipal supplies, irrigation and industrial use. Although the regional flow system can be characterized generally as east to northeasterly from the Rocky Mountains towards the Missouri River, locally the flow systems are hydrologically complex. This study uses Sr isotopic data from groundwater and leached aquifer samples to document the complex subsystems within the Dakota aquifer in Nebraska and Kansas. The interaction of groundwater with the geologic material through which it flows has created spatial patterns in the isotopic measurements that are related to: long-term water-rock interaction, during which varying degrees of isotopic equilibrium between water and rock has been achieved; and the alteration of NaCl fluids by water-rock interaction. Specifically, Sr isotopic data distinguish brines from Kansas and western Nebraska from those in eastern Nebraska: the former are interpreted to reflect interaction with Permian rocks, whereas the latter record interaction with Pennsylvanian rocks. The Sr isotopic composition of groundwater from other parts of Nebraska and Kansas are a function of the dynamic interaction between groundwater and unlithified sediments (e.g., glacial till and loess), followed by interaction with oxidized and unoxidized sediments within the Dakota Formation. This study illustrates the power of combining Sr chemistry with more conventional geochemical data to obtain a more complete understanding of groundwater flow systems within regional aquifer systems where extensive monitoring networks do not exist

  9. Studying groundwater and surface water interactions using airborne remote sensing in Heihe River basin, northwest China

    OpenAIRE

    Liu, C.; Liu, J.; Hu, Y.; Zheng, C.

    2015-01-01

    Managing surface water and groundwater as a unified system is important for water resource exploitation and aquatic ecosystem conservation. The unified approach to water management needs accurate characterization of surface water and groundwater interactions. Temperature is a natural tracer for identifying surface water and groundwater interactions, and the use of remote sensing techniques facilitates basin-scale temperature measurement. This study focuses on the Heihe River basin, the second...

  10. Groundwater quality in the Columbia Plateau, Snake River Plain, and Oahu basaltic-rock and basin-fill aquifers in the Northwestern United States and Hawaii, 1992-2010

    Science.gov (United States)

    Frans, Lonna M.; Rupert, Michael G.; Hunt, Charles D.; Skinner, Kenneth D.

    2012-01-01

    This assessment of groundwater-quality conditions of the Columbia Plateau, Snake River Plain, and Oahu for the period 1992–2010 is part of the U.S. Geological Survey’s National Water Quality Assessment (NAWQA) program. It shows where, when, why, and how specific water-quality conditions occur in groundwater of the three study areas and yields science-based implications for assessing and managing the quality of these water resources. The primary aquifers in the Columbia Plateau, Snake River Plain, and Oahu are mostly composed of fractured basalt, which makes their hydrology and geochemistry similar. In spite of the hydrogeologic similarities, there are climatic differences that affect the agricultural practices overlying the aquifers, which in turn affect the groundwater quality. Understanding groundwater-quality conditions and the natural and human factors that control groundwater quality is important because of the implications to human health, the sustainability of rural agricultural economies, and the substantial costs associated with land and water management, conservation, and regulation.

  11. Ground-Water Flow Model for the Spokane Valley-Rathdrum Prairie Aquifer, Spokane County, Washington, and Bonner and Kootenai Counties, Idaho

    Science.gov (United States)

    Hsieh, Paul A.; Barber, Michael E.; Contor, Bryce A.; Hossain, Md. Akram; Johnson, Gary S.; Jones, Joseph L.; Wylie, Allan H.

    2007-01-01

    This report presents a computer model of ground-water flow in the Spokane Valley-Rathdrum Prairie (SVRP) aquifer in Spokane County, Washington, and Bonner and Kootenai Counties, Idaho. The aquifer is the sole source of drinking water for more than 500,000 residents in the area. In response to the concerns about the impacts of increased ground-water withdrawals resulting from recent and projected urban growth, a comprehensive study was initiated by the Idaho Department of Water Resources, the Washington Department of Ecology, and the U.S. Geological Survey to improve the understanding of ground-water flow in the aquifer and of the interaction between ground water and surface water. The ground-water flow model presented in this report is one component of this comprehensive study. The primary purpose of the model is to serve as a tool for analyzing aquifer inflows and outflows, simulating the effects of future changes in ground-water withdrawals from the aquifer, and evaluating aquifer management strategies. The scale of the model and the level of detail are intended for analysis of aquifer-wide water-supply issues. The SVRP aquifer model was developed by the Modeling Team formed within the comprehensive study. The Modeling Team consisted of staff and personnel working under contract with the Idaho Department of Water Resources, personnel working under contract with the Washington Department of Ecology, and staff of the U.S. Geological Survey. To arrive at a final model that has the endorsement of all team members, decisions on modeling approach, methodology, assumptions, and interpretations were reached by consensus. The ground-water flow model MODFLOW-2000 was used to simulate ground-water flow in the SVPR aquifer. The finite-difference model grid consists of 172 rows, 256 columns, and 3 layers. Ground-water flow was simulated from September 1990 through September 2005 using 181 stress periods of 1 month each. The areal extent of the model encompasses an area of

  12. The use of Magnetic Resonance Sounding in shallow aquifers IN THE Duero RIVER Basin; Aplicacion de sondeos de resonancia magnetica en acuiferos superficiales de la Cuenca del Duero

    Energy Technology Data Exchange (ETDEWEB)

    Uriarte Blanco, C.; Plata Torres, J. L.; Diaz-Curiel, J.; Martinez-Fernandez, J.

    2011-07-01

    To manage the water resources of a region efficiently it is vital to be aware of the dynamics and evolution of its groundwater. To this end groundwater models are used, but these models require information about the geometry and hydraulic parameters of the aquifer, which is generally quite expensive to obtain. Magnetic resonance sounding (MRS) is a non-invasive geophysical technique that allows an aquifer to be characterized. Our intention here is to assess the use of this geophysical technique to optimize the acquisition of data when preparing a hydrological model of surface aquifers in the Duero Basin. The study was undertaken in the Experimental Basin of Carrizal, within the Los Arenales aquifer in the Duero Basin. We present a detailed analysis and interpretation of the MRS results, which have provided us with information concerning the parameters needed to establish a hydrological model of the aquifer, information that may be used eventually as an input to obtain a hydrological model of the whole basin. (Author)

  13. Delineation of spatial-temporal patterns of groundwater/surface-water interaction along a river reach (Aa River, Belgium) with transient thermal modeling

    Science.gov (United States)

    Anibas, Christian; Tolche, Abebe Debele; Ghysels, Gert; Nossent, Jiri; Schneidewind, Uwe; Huysmans, Marijke; Batelaan, Okke

    2017-12-01

    Among the advances made in analytical and numerical analysis methods to quantify groundwater/surface-water interaction, one methodology that stands out is the use of heat as an environmental tracer. A large data set of river and riverbed temperature profiles from the Aa River in Belgium has been used to examine the spatial-temporal variations of groundwater/surface-water interaction. Exchange fluxes were calculated with the numerical heat-transport code STRIVE. The code was applied in transient mode to overcome previous limitations of steady-state analysis, and allowed for the calculation of model quality. In autumn and winter the mean exchange fluxes reached -90 mm d-1, while in spring and early summer fluxes were -42 mm d-1. Predominantly gaining conditions occurred along the river reach; however, in a few areas the direction of flow changed in time. The river banks showed elevated fluxes up to a factor of 3 compared to the center of the river. Higher fluxes were detected in the upstream section of the reach. Due to the influence of exchange fluxes along the river banks, larger temporal variations were found in the downstream section. The exchange fluxes at the river banks seemed more driven by variable local exchange flows, while the center of the river was dominated by deep and steady regional groundwater flows. These spatial and temporal differences in groundwater/surface-water exchange show the importance of long-term investigations on the driving forces of hyporheic processes across different scales.

  14. Delineation of spatial-temporal patterns of groundwater/surface-water interaction along a river reach (Aa River, Belgium) with transient thermal modeling

    Science.gov (United States)

    Anibas, Christian; Tolche, Abebe Debele; Ghysels, Gert; Nossent, Jiri; Schneidewind, Uwe; Huysmans, Marijke; Batelaan, Okke

    2018-05-01

    Among the advances made in analytical and numerical analysis methods to quantify groundwater/surface-water interaction, one methodology that stands out is the use of heat as an environmental tracer. A large data set of river and riverbed temperature profiles from the Aa River in Belgium has been used to examine the spatial-temporal variations of groundwater/surface-water interaction. Exchange fluxes were calculated with the numerical heat-transport code STRIVE. The code was applied in transient mode to overcome previous limitations of steady-state analysis, and allowed for the calculation of model quality. In autumn and winter the mean exchange fluxes reached -90 mm d-1, while in spring and early summer fluxes were -42 mm d-1. Predominantly gaining conditions occurred along the river reach; however, in a few areas the direction of flow changed in time. The river banks showed elevated fluxes up to a factor of 3 compared to the center of the river. Higher fluxes were detected in the upstream section of the reach. Due to the influence of exchange fluxes along the river banks, larger temporal variations were found in the downstream section. The exchange fluxes at the river banks seemed more driven by variable local exchange flows, while the center of the river was dominated by deep and steady regional groundwater flows. These spatial and temporal differences in groundwater/surface-water exchange show the importance of long-term investigations on the driving forces of hyporheic processes across different scales.

  15. Assessment of groundwater–surface water interaction using long-term hydrochemical data and isotope hydrology: Headwaters of the Condamine River, Southeast Queensland, Australia

    Energy Technology Data Exchange (ETDEWEB)

    Martinez, Jorge L., E-mail: jlmarti@ig.com.br [Queensland University of Technology, Brisbane (Australia); Raiber, Matthias [CSIRO Land and Water Flagship, Brisbane (Australia); Cox, Malcolm E. [Queensland University of Technology, Brisbane (Australia)

    2015-12-01

    A spatial analysis of hydrochemical data of groundwater and surface water was undertaken to identify groundwater-surface water connectivity in the headwaters of the Condamine River catchment, Southeast Queensland, Australia. An assessment of long-term hydrochemical and water level data supplemented by stable- and radioisotope measurements following a prolonged dry period dominated by baseflow, helped in determining patterns of interaction in different tributaries of the upper Condamine catchment. A conceptual hydrological model representing the major hydrochemical processes and their implications for stream-aquifer connectivity was developed and tested using multiple lines of evidence. The results of a multivariate statistical analysis highlight that there are two main regions with distinct hydrochemical facies (salinity, alkalinity, and predominant ions) in surface water. Geomorphology, geology, anthropogenic and climate influence were identified as the most relevant controlling factors of the spatial variability in water quality. Stable isotope data confirmed a clear evaporation trend in almost all surface water samples during baseflow conditions. Two water types can be identified and separated by the degree of evaporation and the proximity of one group to the local meteoric water line. The results confirm the discharge of groundwater from aquifers recharged by rainfall and located upstream of the surface water sampling sites. Overall, {sup 222}Rn data show a trend of increased activity in surface water towards the upstream portions of these tributaries, validating the use of this tracer to estimate groundwater input to the local creeks. The proportion of groundwater contribution to stream flow calculated by {sup 222}Rn and chloride mass balance is in agreement, and ranges between 20–70% in tributaries in the northern areas, and between 8–50% in the upper reaches of the main river channel. This study shows the efficacy of an integrated approach combining long

  16. Assessment of groundwater–surface water interaction using long-term hydrochemical data and isotope hydrology: Headwaters of the Condamine River, Southeast Queensland, Australia

    International Nuclear Information System (INIS)

    Martinez, Jorge L.; Raiber, Matthias; Cox, Malcolm E.

    2015-01-01

    A spatial analysis of hydrochemical data of groundwater and surface water was undertaken to identify groundwater-surface water connectivity in the headwaters of the Condamine River catchment, Southeast Queensland, Australia. An assessment of long-term hydrochemical and water level data supplemented by stable- and radioisotope measurements following a prolonged dry period dominated by baseflow, helped in determining patterns of interaction in different tributaries of the upper Condamine catchment. A conceptual hydrological model representing the major hydrochemical processes and their implications for stream-aquifer connectivity was developed and tested using multiple lines of evidence. The results of a multivariate statistical analysis highlight that there are two main regions with distinct hydrochemical facies (salinity, alkalinity, and predominant ions) in surface water. Geomorphology, geology, anthropogenic and climate influence were identified as the most relevant controlling factors of the spatial variability in water quality. Stable isotope data confirmed a clear evaporation trend in almost all surface water samples during baseflow conditions. Two water types can be identified and separated by the degree of evaporation and the proximity of one group to the local meteoric water line. The results confirm the discharge of groundwater from aquifers recharged by rainfall and located upstream of the surface water sampling sites. Overall, 222 Rn data show a trend of increased activity in surface water towards the upstream portions of these tributaries, validating the use of this tracer to estimate groundwater input to the local creeks. The proportion of groundwater contribution to stream flow calculated by 222 Rn and chloride mass balance is in agreement, and ranges between 20–70% in tributaries in the northern areas, and between 8–50% in the upper reaches of the main river channel. This study shows the efficacy of an integrated approach combining long

  17. Understanding Interactions between Hydrogeologic Factors, Design Variables, and System Operations for Multi-Well Aquifer Storage and Recovery Systems

    Science.gov (United States)

    Majumdar, S.; Miller, G. R.; Smith, B.; Sheng, Z.

    2017-12-01

    Aquifer Storage and Recovery (ASR) system is a powerful tool for managing our present and future freshwater supplies. It involves injection of excess water into an aquifer, storing and later recovering it when needed, such as in a drought or during peak demand periods. Multi-well ASR systems, such as the Twin Oaks Facility in San Antonio, consist of a group of wells that are used for simultaneous injection and extraction of stored water. While significant research has gone into examining the effects of hydraulic and operational factors on recovery efficiency for single ASR well, little is known about how multi-well systems respond to these factors and how energy uses may vary. In this study, we created a synthetic ASR model in MODFLOW to test a range of multi-well scenarios. We altered design parameters (well spacing, pumping capacity, well configuration), hydrogeologic factors (regional hydraulic gradient, hydraulic conductivity, dispersivity), and operational variables (injection and withdrawal durations; pumping rates) to determine the response of the system across a realistic range of interrelated parameters. We then computed energy use for each simulation, based on the hydraulic head in each well and standard pump factors, as well as recovery efficiency, based on tracer concentration in recovered water from the wells. The tracer concentration in the groundwater was determined using MT3DMS. We observed that the recovery and energy efficiencies for the Multi-well ASR system decrease with the increase in well spacing and hydraulic gradient. When longitudinal dispersivity was doubled, the recovery and energy efficiencies were nearly halved. Another finding from our study suggests that we can recover nearly 90% of the water after two successive cycles of operation. The results will be used to develop generalized operational guidelines for meeting freshwater demands and also optimise the energy consumed during pumping.

  18. Springwater geochemistry at Honey Creek State Natural Area, central Texas: Implications for surface water and groundwater interaction in a karst aquifer

    Science.gov (United States)

    Musgrove, M.; Stern, L. A.; Banner, J. L.

    2010-06-01

    SummaryA two and a half year study of two adjacent watersheds at the Honey Creek State Natural Area (HCSNA) in central Texas was undertaken to evaluate spatial and temporal variations in springwater geochemistry, geochemical evolution processes, and potential effects of brush control on karst watershed hydrology. The watersheds are geologically and geomorphologically similar, and each has springs discharging into Honey Creek, a tributary to the Guadalupe River. Springwater geochemistry is considered in a regional context of aquifer components including soil water, cave dripwater, springwater, and phreatic groundwater. Isotopic and trace element variability allows us to identify both vadose and phreatic groundwater contributions to surface water in Honey Creek. Spatial and temporal geochemical data for six springs reveal systematic differences between the two watersheds. Springwater Sr isotope values lie between values for the limestone bedrock and soils at HCSNA, reflecting a balance between these two primary sources of Sr. Sr isotope values for springs within each watershed are consistent with differences between soil compositions. At some of the springs, consistent temporal variability in springwater geochemistry (Sr isotopes, Mg/Ca, and Sr/Ca values) appears to reflect changes in climatic and hydrologic parameters (rainfall/recharge) that affect watershed processes. Springwater geochemistry was unaffected by brush removal at the scale of the HCSNA study. Results of this study build on previous regional studies to provide insight into watershed hydrology and regional hydrologic processes, including connections between surface water, vadose groundwater, and phreatic groundwater.

  19. An Update of Hydrologic Conditions and Distribution of Selected Constituents in Water, Snake River Plain Aquifer and Perched-Water Zones, Idaho National Laboratory, Idaho, Emphasis 2002-05

    Science.gov (United States)

    Davis, Linda C.

    2008-01-01

    Radiochemical and chemical wastewater discharged since 1952 to infiltration ponds, evaporation ponds, and disposal wells at the Idaho National Laboratory (INL) has affected water quality in the Snake River Plain aquifer and perched-water zones underlying the INL. The U.S. Geological Survey, in cooperation with the U.S. Department of Energy, maintains ground-water monitoring networks at the INL to determine hydrologic trends, and to delineate the movement of radiochemical and chemical wastes in the aquifer and in perched-water zones. This report presents an analysis of water-level and water-quality data collected from aquifer and perched-water wells in the USGS ground-water monitoring networks during 2002-05. Water in the Snake River Plain aquifer primarily moves through fractures and interflow zones in basalt, generally flows southwestward, and eventually discharges at springs along the Snake River. The aquifer is recharged primarily from infiltration of irrigation water, infiltration of streamflow, ground-water inflow from adjoining mountain drainage basins, and infiltration of precipitation. From March-May 2001 to March-May 2005, water levels in wells declined throughout the INL area. The declines ranged from about 3 to 8 feet in the southwestern part of the INL, about 10 to 15 feet in the west central part of the INL, and about 6 to 11 feet in the northern part of the INL. Water levels in perched water wells declined also, with the water level dropping below the bottom of the pump in many wells during 2002-05. For radionuclides, concentrations that equal 3s, wheres s is the sample standard deviation, represent a measurement at the minimum detectable concentration, or 'reporting level'. Detectable concentrations of radiochemical constituents in water samples from wells in the Snake River Plain aquifer at the INL generally decreased or remained constant during 2002-05. Decreases in concentrations were attributed to decreased rates of radioactive-waste disposal

  20. Interaction of water components in the semi-arid Huasco and Limarí river basins, North Central Chile

    Directory of Open Access Journals (Sweden)

    G. Strauch

    2009-10-01

    Full Text Available For sustainable water resource management in semi-arid regions, sound information is required about interactions between the different components of the water system: rain/snow precipitation, surface/subsurface run-off, groundwater recharge. Exemplarily, the Huasco and Limarí river basins as water stressed river catchments have been studied by isotope and hydrochemical methods for (i the origin of water, (ii water quality, (iii relations of surface and groundwater.

    Applying the complex multi-isotopic and hydrochemical methodology to the water components of the Huasco and Limarí basins, a differentiation of water components concerning subsurface flow and river water along the catchment area and by anthropogenic impacts are detected. Sulphate and nitrate concentrations indicate remarkable input from mining and agricultural activities along the river catchment.

    The 2H-18O relations of river water and groundwater of both catchments point to the behaviour of river waters originated in an arid to semi-arid environment.

    Consequently, the groundwater from several production wells in the lower parts of the catchments is related to the rivers where the wells located, however, it can be distinguished from the river water. Using the hydrological water balance and the isotope mixing model, the interaction between surface and subsurface flows and river flow is estimated.

  1. Estimating Aquifer Properties Using Sinusoidal Pumping Tests

    Science.gov (United States)

    Rasmussen, T. C.; Haborak, K. G.; Young, M. H.

    2001-12-01

    We develop the theoretical and applied framework for using sinusoidal pumping tests to estimate aquifer properties for confined, leaky, and partially penetrating conditions. The framework 1) derives analytical solutions for three boundary conditions suitable for many practical applications, 2) validates the analytical solutions against a finite element model, 3) establishes a protocol for conducting sinusoidal pumping tests, and 4) estimates aquifer hydraulic parameters based on the analytical solutions. The analytical solutions to sinusoidal stimuli in radial coordinates are derived for boundary value problems that are analogous to the Theis (1935) confined aquifer solution, the Hantush and Jacob (1955) leaky aquifer solution, and the Hantush (1964) partially penetrated confined aquifer solution. The analytical solutions compare favorably to a finite-element solution of a simulated flow domain, except in the region immediately adjacent to the pumping well where the implicit assumption of zero borehole radius is violated. The procedure is demonstrated in one unconfined and two confined aquifer units near the General Separations Area at the Savannah River Site, a federal nuclear facility located in South Carolina. Aquifer hydraulic parameters estimated using this framework provide independent confirmation of parameters obtained from conventional aquifer tests. The sinusoidal approach also resulted in the elimination of investigation-derived wastes.

  2. Simulation of Regional Ground-Water Flow in the Suwannee River Basin, Northern Florida and Southern Georgia

    Science.gov (United States)

    Planert, Michael

    2007-01-01

    -lying surficial and underlying Upper Floridan aquifers. The Upper Floridan aquifer is present throughout the study area and is extremely permeable and typically capable of transmitting large volumes of water. This high permeability largely is due to the widening of fractures and formation of conduits within the aquifer through dissolu-tion of the limestone by infiltrating water. This process has also produced numerous karst features such as springs, sinking streams, and sinkholes. A model of the Upper Floridan aquifer was created to better understand the ground-water system and to provide resource managers a tool to evaluate ground-water and surface-water interactions in the Suwannee River Basin. The model was developed to simulate a single Upper Floridan aquifer layer. Recharge datasets were developed to represent a net flux of water to the top of the aquifer or the water table during a period when the system was assumed to be under steady-state conditions (September 1990). A potentiometric-surface map representing water levels during September 1990 was prepared for the Suwannee River Water Management District (SRWMD), and the heads from those wells were used for calibration of the model. Additionally, flows at gaging sites for the Suwannee, Alapaha, Withlacoochee, Santa Fe, Fenholloway, Aucilla, Ecofina, and Steinhatchee Rivers were used during the calibration process to compare to model computed flows. Flows at seven first-magnitude springs selected by the SRWMD also were used to calibrate the model. Calibration criterion for matching potentiometric heads was to attain an absolute residual mean error of 5 percent or less of the head gradient of the system which would be about 5 feet. An absolute residual mean error of 4.79 feet was attained for final calibration. Calibration criterion for matching streamflow was based on the quality of measurements made in the field. All measurements used were rated ?good,? so the desire was for simulated values to be wi

  3. Surface water / groundwater interactions and their spatial variability, an example from the Avon River, South-East Australia

    Science.gov (United States)

    Hofmann, Harald; Cartwright, Ian; Gilfedder, Benjamin

    2013-04-01

    Understanding the interaction between river water and regional groundwater has significant importance for water management and resource allocation. The dynamics of groundwater/surface water interactions also have implications for ecosystems, pollutant transport, and the quality and quantity of water supply for domestic, agriculture and recreational purposes. After general assumptions and for management purposes rivers are classified in loosing or gaining rivers. However, many streams alternate between gaining and loosing conditions on a range of temporal and spatial scales due to factors including: 1) river water levels in relation to groundwater head; 2) the relative response of the groundwater and river system to rainfall; 3) heterogeneities in alluvial sediments that can lead to alternation of areas of exfiltration and infiltration along a river stretch; and 4) differences in near river reservoirs, such parafluvial flow and bank storage. Spatial variability of groundwater discharge to rivers is rarely accounted for as it is assumed that groundwater discharge is constant over river stretches and only changes with the seasonal river water levels. Riverbank storage and parafluvial flow are generally not taken in consideration. Bank storage has short-term cycles and can contribute significantly to the total discharge, especially after flood events. In this study we used hydrogeochemistry to constrain spatial and temporal differences in gaining and loosing conditions in rivers and investigate potential sources. Environmental tracers, such as major ion chemistry, stables isotopes and Radon are useful tools to characterise these sources. Surface water and ground water samples were taken in the Avon River in the Gippsland Basin, Southwest Australia. Increasing TDS along the flow path from 70 to 250 mg/l, show that the Avon is a net gaining stream. The radon concentration along the river is variable and does not show a general increase downstream, but isolated peaks in

  4. Potential interaction between transport and stream networks over the lowland rivers in Eastern India.

    Science.gov (United States)

    Roy, Suvendu; Sahu, Abhay Sankar

    2017-07-15

    Extension of transport networks supports good accessibility and associated with the development of a region. However, transport lines have fragmented the regional landscape and disturbed the natural interplay between rivers and their floodplains. Spatial analysis using multiple buffers provides information about the potential interaction between road and stream networks and their impact on channel morphology of a small watershed in the Lower Gangetic Plain. Present study is tried to understand the lateral and longitudinal disconnection in headwater stream by rural roads with the integration of geoinformatics and field survey. Significant (p development, delineation of stream corridor, regular monitoring and engineering efficiency for the construction of road and road-stream crossing might be effective in managing river geomorphology and riverine landscape. Copyright © 2017 Elsevier Ltd. All rights reserved.

  5. Recalibration of a ground-water flow model of the Mississippi River Valley alluvial aquifer in Southeastern Arkansas, 1918, with simulations of hydraulic heads caused by projected ground-water withdrawals through 2049

    Science.gov (United States)

    Stanton, Gregory P.; Clark, Brian R.

    2003-01-01

    The Mississippi River Valley alluvial aquifer, encompassing parts of Arkansas, Kentucky, Louisiana, Mississippi, Missouri, and Tennessee supplies an average of 5 billion gallons of water per day. However, withdrawals from the aquifer in recent years have caused considerable drawdown in the hydraulic heads in southeastern Arkansas and other areas. The effects of current ground-water withdrawals and potential future withdrawals on water availability are major concerns of water managers and users as well as the general public. A full understanding of the behavior of the aquifer under various water-use scenarios is critical for the development of viable water-management and alternative source plans. To address these concerns, the U.S. Geological Survey, in cooperation with the U.S. Army Corps of Engineers, Vicksburg District, and the Arkansas Soil and Water Conservation Commission developed and calibrated a ground-water flow model for the Mississippi River valley alluvial aquifer in southeastern Arkansas to simulate hydraulic heads caused by projected ground-water withdrawals. A previously published ground-water flow model for the alluvial aquifer in southeastern Arkansas was updated and recalibrated to reflect more current pumping stresses with additional stress periods added to bring the model forward from 1982 to 1998. The updated model was developed and calibrated with MODFLOW-2000 finite difference numerical modeling and parameter estimation software. The model was calibrated using hydraulic-head data collected during 1972 and 1982 and hydraulic-head measurements made during spring (February to April) of 1992 and 1998. The residuals for 1992 and 1998 have a mean absolute value of 4.74 and 5.45 feet, respectively, and a root mean square error of 5.9 and 6.72 feet, respectively. The effects of projected ground-water withdrawals were simulated through 2049 in three predictive scenarios by adding five additional stress periods of 10 years each. In the three scenarios

  6. Characterization of the interactions between endocrine disruptors and aquatic humic substances from tropical rivers

    International Nuclear Information System (INIS)

    Botero, Wander G.; Oliveira, Luciana C. de; Cunha, Bruno B.; Oliveira, Lilian K. de; Goveia, Danielle; Fraceto, Leonardo F.; Rosa, Andre Henrique; Rocha, Julio Cesar

    2011-01-01

    Interactions between two endocrine disruptors (ED) and aquatic humic substances (AHS) from tropical rivers were studied using an ultrafiltration system equipped with a 1 kDa cut-off cellulose membrane to separate free ED from the fraction bound in the AHS. Quantification of 17α-ethynylestradiol and bisphenol A was performed using gas chromatography-mass spectrometry (GC-MS). The times required for establishment of equilibrium between the AHS and the ED were ca. 30 min, and complexation capacities for 17α-ethynylestradiol and bisphenol A were 18.53 and 2.07 mg g -1 TOC, respectively. The greater interaction of AHS with 17α-ethynylestradiol, compared to bisphenol A, was due to the presence of hydrogen in the structure of 17α-ethynylestradiol, which could interact with ionized oxygenated groups of the AHS. The results indicate that AHS can strongly influence the transport and reactivity of endocrine disruptors in aquatic systems. (author)

  7. An update of hydrologic conditions and distribution of selected constituents in water, eastern Snake River Plain aquifer and perched groundwater zones, Idaho National Laboratory, Idaho, emphasis 2009–11

    Science.gov (United States)

    Davis, Linda C.; Bartholomay, Roy C.; Rattray, Gordon W.

    2013-01-01

    Since 1952, wastewater discharged to infiltration ponds (also called percolation ponds) and disposal wells at the Idaho National Laboratory (INL) has affected water quality in the eastern Snake River Plain (ESRP) aquifer and perched groundwater zones underlying the INL. The U.S. Geological Survey (USGS), in cooperation with the U.S. Department of Energy, maintains groundwater monitoring networks at the INL to determine hydrologic trends, and to delineate the movement of radiochemical and chemical wastes in the aquifer and in perched groundwater zones. This report presents an analysis of water-level and water-quality data collected from aquifer, multilevel monitoring system (MLMS), and perched groundwater wells in the USGS groundwater monitoring networks during 2009–11. Water in the ESRP aquifer primarily moves through fractures and interflow zones in basalt, generally flows southwestward, and eventually discharges at springs along the Snake River. The aquifer primarily is recharged from infiltration of irrigation water, infiltration of streamflow, groundwater inflow from adjoining mountain drainage basins, and infiltration of precipitation. From March–May 2009 to March–May 2011, water levels in wells generally declined in the northern part of the INL. Water levels generally rose in the central and eastern parts of the INL. Detectable concentrations of radiochemical constituents in water samples from aquifer wells or MLMS equipped wells in the ESRP aquifer at the INL generally decreased or remained constant during 2009–11. Decreases in concentrations were attributed to radioactive decay, changes in waste-disposal methods, and dilution from recharge and underflow. In 2011, concentrations of tritium in groundwater from 50 of 127 aquifer wells were greater than or equal to the reporting level and ranged from 200±60 to 7,000±260 picocuries per liter. Tritium concentrations from one or more discrete zones from four wells equipped with MLMS were greater than or

  8. Balancing riparian management and river recreation: methods and applications for exploring floater behavior and their interaction with large wood.

    Science.gov (United States)

    Biedenweg, Kelly; Akyuz, Kate; Skeele, Rebecca

    2012-08-01

    River managers are tasked with meeting both ecological and human needs. In the Puget Sound lowland, riparian management often includes placing or allowing the presence of large wood to stabilize riverbanks and enhance salmon habitat. Although this practice benefits humans by protecting infrastructure and natural resources, it is unclear how such practices interact with an additional human interest, recreation. Furthermore, we were unable to find studies that describe how an agency can go about researching the interaction between recreation and large wood management practices. This study tested methods for describing and estimating the number of river floaters, where they float in relationship to river projects, the risks they take while floating, and their perceptions of large wood in the river. Selecting a high-use suburban river in Washington State, we used riverside observations, interviews, and an infrared counter to gather data in the summer of 2010. Statistical analyses provided general characteristics of users, trends in engaging in risky behaviors, and estimates of use for the entire season and on the busiest day. Data mapping with GIS presented the density of use along the river and frequency of use of specific float routes. Finally, qualitative analysis of interviews clarified floaters' perspectives of large wood. To address the multiple mandates of river managers, it is important to understand recreation users, the factors that could be putting them at risk, and how the actual users perceive large wood in the river. This study demonstrates methods for scientifically gathering such information and applying it when making riparian management decisions.

  9. Hydrological connectivity of perched aquifers and regional aquifers in semi-arid environments: a case study from Namibia

    Science.gov (United States)

    Hamutoko, J. T.; Wanke, H.

    2017-12-01

    Integrated isotopic and hydrological tracers along with standard hydrological data are used to understand complex dry land hydrological processes on different spatial and temporal scales. The objective of this study is to analyse the relationship between the perched aquifers and the regional aquifer using hydrochemical data and isotopic composition in the Cuvelai-Etosha Basin in Namibia. This relation between the aquifers will aid in understanding groundwater recharge processes and flow dynamics. Perched aquifers are discontinuous shallow aquifers with water level ranging from 0 to 30 meters below ground level. The regional aquifer occurs in semi-consolidated sandstone at depths between about 60 and 160 meters below ground level. Water samples were collected from both aquifers in 10 villages and were analysed for major ions and stable isotopes. The results show overlapping hydrochemistry and isotopic compositions of both aquifers in 8 villages which suggest the possibility of perched aquifer water infiltrating into the regional aquifer. In two villages the hydrochemistry and isotopic composition of the aquifers are totally different and this suggests that there is no interaction between this aquifers. Areas where perched aquifers are connected to regional aquifers maybe recharge zones. These finding have important implications for groundwater resource management.

  10. Probability of Unmixed Young Groundwater (defined using chlorofluorocarbon-11 concentrations and tritium activities) in the Eagle River Watershed Valley-Fill Aquifer, Eagle County, North-Central Colorado, 2006-2007

    Science.gov (United States)

    Rupert, Michael G.; Plummer, Niel

    2009-01-01

    This raster data set delineates the predicted probability of unmixed young groundwater (defined using chlorofluorocarbon-11 concentrations and tritium activities) in groundwater in the Eagle River watershed valley-fill aquifer, Eagle County, North-Central Colorado, 2006-2007. This data set was developed by a cooperative project between the U.S. Geological Survey, Eagle County, the Eagle River Water and Sanitation District, the Town of Eagle, the Town of Gypsum, and the Upper Eagle Regional Water Authority. This project was designed to evaluate potential land-development effects on groundwater and surface-water resources so that informed land-use and water management decisions can be made. This groundwater probability map and its associated probability maps were developed as follows: (1) A point data set of wells with groundwater quality and groundwater age data was overlaid with thematic layers of anthropogenic (related to human activities) and hydrogeologic data by using a geographic information system to assign each well values for depth to groundwater, distance to major streams and canals, distance to gypsum beds, precipitation, soils, and well depth. These data then were downloaded to a statistical software package for analysis by logistic regression. (2) Statistical models predicting the probability of elevated nitrate concentrations, the probability of unmixed young water (using chlorofluorocarbon-11 concentrations and tritium activities), and the probability of elevated volatile organic compound concentrations were developed using logistic regression techniques. (3) The statistical models were entered into a GIS and the probability map was constructed.

  11. River water infiltration enhances denitrification efficiency in riparian groundwater.

    Science.gov (United States)

    Trauth, Nico; Musolff, Andreas; Knöller, Kay; Kaden, Ute S; Keller, Toralf; Werban, Ulrike; Fleckenstein, Jan H

    2018-03-01

    Nitrate contamination in ground- and surface water is a persistent problem in countries with intense agriculture. The transition zone between rivers and their riparian aquifers, where river water and groundwater interact, may play an important role in mediating nitrate exports, as it can facilitate intensive denitrification, which permanently removes nitrate from the aquatic system. However, the in-situ factors controlling riparian denitrification are not fully understood, as they are often strongly linked and their effects superimpose each other. In this study, we present the evaluation of hydrochemical and isotopic data from a 2-year sampling period of river water and groundwater in the riparian zone along a 3rd order river in Central Germany. Based on bi- and multivariate statistics (Spearman's rank correlation and partial least squares regression) we can show, that highest rates for oxygen consumption and denitrification in the riparian aquifer occur where the fraction of infiltrated river water and at the same time groundwater temperature, are high. River discharge and depth to groundwater are additional explanatory variables for those reaction rates, but of minor importance. Our data and analyses suggest that at locations in the riparian aquifer, which show significant river water infiltration, heterotrophic microbial reactions in the riparian zone may be fueled by bioavailable organic carbon derived from the river water. We conclude that interactions between rivers and riparian groundwater are likely to be a key control of nitrate removal and should be considered as a measure to mitigate high nitrate exports from agricultural catchments. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. Groundwater/surface-water interactions in the Bad River Watershed, Wisconsin

    Science.gov (United States)

    Leaf, Andrew T.; Fienen, Michael N.; Hunt, Randall J.; Buchwald, Cheryl A.

    2015-11-23

    A groundwater-flow model was developed for the Bad River Watershed and surrounding area by using the U.S. Geological Survey (USGS) finite-difference code MODFLOW-NWT. The model simulates steady-state groundwater-flow and base flow in streams by using the streamflow routing (SFR) package. The objectives of this study were to: (1) develop an improved understanding of the groundwater-flow system in the Bad River Watershed at the regional scale, including the sources of water to the Bad River Band of Lake Superior Chippewa Reservation (Reservation) and groundwater/surface-water interactions; (2) provide a quantitative platform for evaluating future impacts to the watershed, which can be used as a starting point for more detailed investigations at the local scale; and (3) identify areas where more data are needed. This report describes the construction and calibration of the groundwater-flow model that was subsequently used for analyzing potential locations for the collection of additional field data, including new observations of water-table elevation for refining the conceptualization and corresponding numerical model of the hydrogeologic system.

  13. Water mass interaction in the confluence zone of the Daning River and the Yangtze River--a driving force for algal growth in the Three Gorges Reservoir.

    Science.gov (United States)

    Holbach, Andreas; Wang, Lijing; Chen, Hao; Hu, Wei; Schleicher, Nina; Zheng, Binghui; Norra, Stefan

    2013-10-01

    Increasing eutrophication and algal bloom events in the Yangtze River Three Gorges Reservoir, China, are widely discussed with regard to changed hydrodynamics and nutrient transport and distribution processes. Insights into water exchange and interaction processes between water masses related to large-scale water level fluctuations in the reservoir are crucial to understand water quality and eutrophication dynamics. Therefore, confluence zones of tributaries with the Yangtze River main stream are dedicated key interfaces. In this study, water quality data were recorded in situ and on-line in varying depths with the MINIBAT towed underwater multi-sensor system in the confluence zone of the Daning River and the Yangtze River close to Wushan City during 1 week in August 2011. Geostatistical evaluation of the water quality data was performed, and results were compared to phosphorus contents of selective water samples. The strongly rising water level throughout the measurement period caused Yangtze River water masses to flow upstream into the tributary and supply their higher nutrient and particulate loads into the tributary water body. Rapid algal growth and sedimentation occurred immediately when hydrodynamic conditions in the confluence zone became more serene again. Consequently, water from the Yangtze River main stream can play a key role in providing nutrients to the algal bloom stricken water bodies of its tributaries.

  14. The thermal consequences of river-level variations in an urban groundwater body highly affected by groundwater heat pumps.

    Science.gov (United States)

    García-Gil, Alejandro; Vázquez-Suñe, Enric; Schneider, Eduardo Garrido; Sánchez-Navarro, José Ángel; Mateo-Lázaro, Jesús

    2014-07-01

    The extensive implementation of ground source heat pumps in urban aquifers is an important issue related to groundwater quality and the future economic feasibility of existent geothermal installations. Although many cities are in the immediate vicinity of large rivers, little is known about the thermal river-groundwater interaction at a kilometric-scale. The aim of this work is to evaluate the thermal impact of river water recharges induced by flood events into an urban alluvial aquifer anthropogenically influenced by geothermal exploitations. The present thermal state of an urban aquifer at a regional scale, including 27 groundwater heat pump installations, has been evaluated. The thermal impacts of these installations in the aquifer together with the thermal impacts from "cold" winter floods have also been spatially and temporally evaluated to ensure better geothermal management of the aquifer. The results showed a variable direct thermal impact from 0 to 6 °C depending on the groundwater-surface water interaction along the river trajectory. The thermal plumes far away from the riverbed also present minor indirect thermal impacts due to hydraulic gradient variations. Copyright © 2014 Elsevier B.V. All rights reserved.

  15. Impeller flow-meter logging of vertical cross flow between basalt aquifers through wells at the Idaho National Engineering Laboratory, Eastern Snake River Plain, Idaho

    International Nuclear Information System (INIS)

    Bennecke, W.M.; Wood, S.H.

    1992-01-01

    An impeller flowmeter was used with a COLOG digital acquisition system to determine existing borehole flows, to compare with previous logging results, and to acquire flow measurements of vertical cross-flow of water in the wells between permeable zones in the open-hole intervals. The direction of flow found was predominantly downward with velocities ranging from 0-30 ft/min. Some flow reversals were noted and attributed to nearby pumping wells. USGS wells 44 and 46 were studied in September, 1991 near the Idaho Chemical Processing Plant (ICPP). The results showed a usual overall flow direction downward with flow entering the wells at around 510 to 600 ft. below the land surface. Water exited these wells at lower levels around 550 to 580 ft. Flow velocities ranged up to 24 ft/min. Using published aquifer parameters, the rate of propagation of a pressure change in an aquifer was calculated for the well CPP-2 turning on and off, at 3100 gpm

  16. Using hydrochemical data and modelling to enhance the knowledge of groundwater flow and quality in an alluvial aquifer of Zagreb, Croatia

    Energy Technology Data Exchange (ETDEWEB)

    Marković, Tamara, E-mail: tmarkovic@hgi-cgs.hr; Brkić, Željka; Larva, Ozren

    2013-08-01

    The Zagreb alluvial aquifer system is located in the southwest of the Pannonian Basin in the Sava Valley in Croatia. It is composed of Quaternary unconsolidated deposits and is highly utilised, primarily as a water supply for the more than one million inhabitants of the capital city of Croatia. To determine the origin and dynamics of the groundwater and to enhance the knowledge of groundwater flow and the interactions between the groundwater and surface water, extensive hydrogeological and hydrochemical investigations have been completed. The groundwater levels monitored in nested observation wells and the lithological profile indicate that the aquifer is a single hydrogeologic unit, but the geochemical characteristics of the aquifer indicate stratification. The weathering of carbonate and silicate minerals has an important role in groundwater chemistry, especially in the area where old meanders of the Sava River existed. Groundwater quality was observed to be better in the deeper parts of the aquifer than in the shallower parts. Furthermore, deterioration of the groundwater quality was observed in the area under the influence of the landfill. The stable isotopic composition of all sampled waters indicates meteoric origin. NETPATH-WIN was used to calculate the mixing proportions between initial waters (water from the Sava River and groundwater from “regional” flow) in the final water (groundwater sampled from observation wells). According to the results, the mixing proportions of “regional” flow and the river water depend on hydrological conditions, the duration of certain hydrological conditions and the vicinity of the Sava River. Moreover, although the aquifer system behaves as a single hydrogeologic unit from a hydraulic point of view, it still clearly demonstrates geochemical stratification, which could be a decisive factor in future utilisation strategies for the aquifer system. - Highlights: • The Zagreb aquifer is the largest utilised source of

  17. The impact of poplar tree plantations for biomass production on the aquifer water budget and base flow in a Mediterranean basin

    Energy Technology Data Exchange (ETDEWEB)

    Folch, Albert, E-mail: folch.hydro@gmail.com [Hydrogeology Group (UPC-CSIC), Department of Geotechnical Engineering and Geo-sciences, Universitat Politècnica de Catalunya-BarcelonaTech, Barcelona (Spain); Institut de Ciència i Tecnologia Ambientals, Universitat Autònoma de Barcelona, Bellaterra (Spain); Ferrer, Núria [Hydrogeology Group (UPC-CSIC), Department of Geotechnical Engineering and Geo-sciences, Universitat Politècnica de Catalunya-BarcelonaTech, Barcelona (Spain)

    2015-08-15

    Poplar plantations are used for biomass production in many countries. These plantations are often located in areas where the tree roots can reach the water table of shallow aquifers to reduce irrigation costs and increase evapotranspiration, mainly during the summer. This study aims to assess the effects of these plantations on an aquifer water budget and on the stream flow of a Mediterranean basin (Santa Coloma River, 321.3 km{sup 2} NE Spain). A numerical flow model was constructed to simulate shallow aquifers and to simulate the stream–aquifer interaction for a period of 9 years. Once the model was calibrated, different land use scenarios, such as deciduous forests, dry farming and irrigated farming, were simulated for comparison. The mass balance shows that poplar extracts an average of 2.40 hm{sup 3} from the aquifer, i.e., approximately 18% of the average recharge of the modelled area. This effect reduces the groundwater flow to the main stream and increases the infiltration from the stream to the aquifer. As a result, there is an average reduction in the main stream flow by 46% during the summer, when the lowest flow occurs and when the river is most sensitive. The results indicate that these impacts should be considered in basin management plans and in evaluating the benefits of this type of biomass production. - Highlights: • Poplar plantations can evapotranspirate aquifer groundwater in semiarid areas • A groundwater flow model is presented to quantify poplars’ impact on the water budget • 20% of the aquifer recharge is consumed by poplars • The main stream flow is reduced up to 46% during summer due to plantations uptake • Biomass production impacts must be considered for evaluating water resources planning.

  18. Science Roles and Interactions in Adaptive Management of Large River Restoration Projects, Midwest United States

    Science.gov (United States)

    Jacobson, R. B.; Galat, D. L.; Smith, C. B.

    2010-12-01

    Most large-river restoration projects include formal or informal implementations of adaptive management strategies which acknowledge uncertainty and use scientific inquiry to learn and refine management options. Although the central role of science in reducing uncertainty is acknowledged in such projects, specific roles and interactions can vary widely, including how science relates to decision-making within the governance of these projects. Our objective is to present some structured generalizations about science roles and interactions as developed from the authors’ experiences in adaptive management of large river restoration in the Midwest United States. Scientific information may be introduced into decision making by scientists acting in any of the three roles common to adaptive management -- action agency representative, stakeholder, or science provider. We have observed that confusion and gridlock can arise when it is unclear if a scientist is acting as an advocate for a stakeholder or management position, or instead as an independent, “honest broker” of science. Although both advocacy and independence are proper and expected in public decision making, it is useful when scientists unambiguously identify their role. While complete scientific independence may be illusory, transparency and peer review can promote the ideal. Transparency comes from setting clear directions and objectives at the decision-making level and defining at the outset how learning will help assess progress and inform decisions. Independent peer reviews of proposals, study plans, and publications serve as a powerful tool to advance scientific independence, even if funding sources present a potential conflict of interest. Selection of experts for scientific advice and review often requires consideration of the balance between benefits of the “outside” expert (independent, knowledgeable but with little specific understanding of the river system), compared to those provided by the

  19. Interactive Technologies of Foreign Language Teaching in Future Marine Specialists’ Training: from Experience of the Danube River Basin Universities

    Directory of Open Access Journals (Sweden)

    Olga Demchenko

    2015-08-01

    Full Text Available The article deals with the investigation of the interactive technologies of foreign language teaching in future marine specialists’ training in the Danube river basin universities. The author gives definitions of the most popular interactive technologies aimed to form communicative competence as a significant component of future mariners’ key competencies. Typology and analysis of some interactive technologies of foreign language teaching in future marine specialists’ training are provided.

  20. Regional groundwater-flow model of the Redwall-Muav, Coconino, and alluvial basin aquifer systems of northern and central Arizona

    Science.gov (United States)

    Pool, D.R.; Blasch, Kyle W.; Callegary, James B.; Leake, Stanley A.; Graser, Leslie F.

    2011-01-01

    A numerical flow model (MODFLOW) of the groundwater flow system in the primary aquifers in northern Arizona was developed to simulate interactions between the aquifers, perennial streams, and springs for predevelopment and transient conditions during 1910 through 2005. Simulated aquifers include the Redwall-Muav, Coconino, and basin-fill aquifers. Perennial stream reaches and springs that derive base flow from the aquifers were simulated, including the Colorado River, Little Colorado River, Salt River, Verde River, and perennial reaches of tributary streams. Simulated major springs include Blue Spring, Del Rio Springs, Havasu Springs, Verde River headwater springs, several springs that discharge adjacent to major Verde River tributaries, and many springs that discharge to the Colorado River. Estimates of aquifer hydraulic properties and groundwater budgets were developed from published reports and groundwater-flow models. Spatial extents of aquifers and confining units were developed from geologic data, geophysical models, a groundwater-flow model for the Prescott Active Management Area, drill logs, geologic logs, and geophysical logs. Spatial and temporal distributions of natural recharge were developed by using a water-balance model that estimates recharge from direct infiltration. Additional natural recharge from ephemeral channel infiltration was simulated in alluvial basins. Recharge at wastewater treatment facilities and incidental recharge at agricultural fields and golf courses were also simulated. Estimates of predevelopment rates of groundwater discharge to streams, springs, and evapotranspiration by phreatophytes were derived from previous reports and on the basis of streamflow records at gages. Annual estimates of groundwater withdrawals for agriculture, municipal, industrial, and domestic uses were developed from several sources, including reported withdrawals for nonexempt wells, estimated crop requirements for agricultural wells, and estimated per

  1. Northern tamarisk beetle (Diorhabda carinulata) and tamarisk (Tamarix spp.) interactions in the Colorado River basin

    Science.gov (United States)

    Nagler, Pamela L.; Nguyen, Uyen; Bateman, Heather L.; Jarchow, Christopher; Glenn, Edward P.; Waugh, William J.; van Riper, Charles

    2018-01-01

    Northern tamarisk beetles (Diorhabda carinulata) were released in the Upper Colorado River Basin in the United States in 2004–2007 to defoliate introduced tamarisk shrubs (Tamarix spp.) in the region’s riparian zones. The primary purpose was to control the invasive shrub and reduce evapotranspiration (ET) by tamarisk in an attempt to increase stream flows. We evaluated beetle–tamarisk interactions with MODIS and Landsat imagery on 13 river systems, with vegetation indices used as indicators of the extent of defoliation and ET. Beetles are widespread and exhibit a pattern of colonize–defoliate–emigrate, so that riparian zones contain a mosaic of completely defoliated, partially defoliated, and refoliated tamarisk stands. Based on satellite data and ET algorithms, mean ET before beetle release (2000–2006) was 416 mm/year compared to postrelease (2007–2015) ET of 355 mm/year (pprojections that ET would be reduced by 300–460 mm/year. Reasons for the lower-than-expected ET reductions are because baseline ET rates are lower than initially projected, and percentage ET reduction is low because tamarisk stands tend to regrow new leaves after defoliation and other plants help maintain canopy cover. Overall reductions in tamarisk green foliage during the study are 21%. However, ET in the Upper Basin has shown a steady decline since 2007 and equilibrium has not yet been reached. Defoliation is now proceeding from the Upper Basin into the Lower Basin at a rate of 40 km/year, much faster than initially projected.

  2. River-groundwater connectivity in a karst system, Wellington, New South Wales, Australia

    Science.gov (United States)

    Keshavarzi, Mohammadreza; Baker, Andy; Kelly, Bryce F. J.; Andersen, Martin S.

    2017-03-01

    The characterization of river-aquifer connectivity in karst environments is difficult due to the presence of conduits and caves. This work demonstrates how geophysical imaging combined with hydrogeological data can improve the conceptualization of surface-water and groundwater interactions in karst terrains. The objective of this study is to understand the association between the Bell River and karst-alluvial aquifer at Wellington, Australia. River and groundwater levels were continuously monitored, and electrical resistivity imaging and water quality surveys conducted. Two-dimensional resistivity imaging mapped the transition between the alluvium and karst. This is important for highlighting the proximity of the saturated alluvial sediments to the water-filled caves and conduits. In the unsaturated zone the resistivity imaging differentiated between air- and sediment-filled karst features, and in the saturated zone it mapped the location of possible water- and sediment-filled caves. Groundwater levels are dynamic and respond quickly to changes in the river stage, implying that there is a strong hydraulic connection, and that the river is losing and recharging the adjacent aquifer. Groundwater extractions (1,370 ML, megalitres, annually) from the alluvial aquifer can cause the groundwater level to fall by as much as 1.5 m in a year. However, when the Bell River flows after significant rainfall in the upper catchment, river-leakage rapidly recharges the alluvial and karst aquifers. This work demonstrates that in complex hydrogeological settings, the combined use of geophysical imaging, hydrograph analysis and geochemical measurements provide insights on the local karst hydrology and groundwater processes, which will enable better water-resource and karst management.

  3. Implementation of a 3d numerical model of a folded multilayer carbonate aquifer

    Science.gov (United States)

    Di Salvo, Cristina; Guyennon, Nicolas; Romano, Emanuele; Bruna Petrangeli, Anna; Preziosi, Elisabetta

    2016-04-01

    fully-3D (with aquitards simulated explicitly and transient flow represented by 3D governing equations). At first, steady state simulation were run under average seasonal recharge. To overcome dry-cell problems in the FULL-3D model, the Newton-Raphson formulation for MODFLOW-2005 was invoked. Steady state calibration was achieved mainly using annual average flow along four streambed's Nera River springs and average water level data available only in two observation wells. Results show that a FULL-3D zoned model was required to match the observed distribution of river base flow. The FULL-3D model was then run in transient conditions (1990-2013) by using monthly spatially distributed recharge estimated using the Thornthwaite-Mather method based on 60 years of climate data. The monitored flow of one spring, used for public water supply, was used as proxy data for reconstruct Nera River hydrogram; proxy-based hydrogram was used for calibration of storage coefficients and further model's parameters adjustment. Once calibrated, the model was run under different aquifer management scenario (i.e., pumping wells planned to be active for water supply); the related risk of depletion of spring discharge and groundwater-surface water interaction was evaluated.

  4. Vertical gradients in water chemistry and age in the Northern High Plains Aquifer, Nebraska, 2003

    Science.gov (United States)

    McMahon, P.B.; Böhlke, J.K.; Carney, C.P.

    2007-01-01

    The northern High Plains aquifer is the primary source of water used for domestic, industrial, and irrigation purposes in parts of Colorado, Kansas, Nebraska, South Dakota, and Wyoming. Despite the aquifer’s importance to the regional economy, fundamental ground-water characteristics, such as vertical gradients in water chemistry and age, remain poorly defined. As part of the U.S. Geological Survey’s National Water-Quality Assessment Program, water samples from nested, short-screen monitoring wells installed in the northern High Plains aquifer were analyzed for major ions, nutrients, trace elements, dissolved organic carbon, pesticides, stable and radioactive isotopes, dissolved gases, and other parameters to evaluate vertical gradients in water chemistry and age in the aquifer. Chemical data and tritium and radiocarbon ages show that water in the aquifer was chemically and temporally stratified in the study area, with a relatively thin zone of recently recharged water (less than 50 years) near the water table overlying a thicker zone of older water (1,800 to 15,600 radiocarbon years). In areas where irrigated agriculture was an important land use, the recently recharged ground water was characterized by elevated concentrations of major ions and nitrate and the detection of pesticide compounds. Below the zone of agricultural influence, major-ion concentrations exhibited small increases with depth and distance along flow paths because of rock/water interactions. The concentration increases were accounted for primarily by dissolved calcium, sodium, bicarbonate, sulfate, and silica. In general, the chemistry of ground water throughout the aquifer was of high quality. None of the approximately 90 chemical constituents analyzed in each sample exceeded primary drinking-water standards.Mass-balance models indicate that changes in groundwater chemistry along flow paths in the aquifer can be accounted for by small amounts of feldspar and calcite dissolution; goethite

  5. User-interactive sediment budgets in a browser: A web application for river science and management

    Science.gov (United States)

    Sibley, David M.; Topping, David; Hines, Megan K.; Garner, Bradley D.

    2015-01-01

    Decision-support tools providing accurate, near-real-time data and user-friendly interactive visualizations are of critical value to resource managers tasked with planning and carrying out management programs in their domain. Creating a system to continuously aggregate datasets and recompute derived values is difficult and error-prone when attempted by hand. To address this need for river managers in support of sediment budgeting, we have created a web-based, open source suite of tools and processes that 1) continually aggregate data of interest, 2) recompute derived values based upon latest available data, and 3) update visualizations on-demand, providing simple front-end tools available to resource managers and the public. For the first time, engineers and scientists can access these tools freely over the web to assist them with planning and adaptive management decisions.

  6. Hydrogeologic and geochemical characterization and evaluation of two arroyos for managed aquifer recharge by surface infiltration in the Pojoaque River Basin, Santa Fe County, New Mexico, 2014–15

    Science.gov (United States)

    Robertson, Andrew J.; Cordova, Jeffrey; Teeple, Andrew; Payne, Jason; Carruth, Rob

    2017-02-22

    In order to provide long-term storage of diverted surface water from the Rio Grande as part of the Aamodt water rights settlement, managed aquifer recharge by surface infiltration in Pojoaque River Basin arroyos was proposed as an option. The initial hydrogeologic and geochemical characterization of two arroyos located within the Pojoaque River Basin was performed in 2014 and 2015 in cooperation with the Bureau of Reclamation to evaluate the potential suitability of these two arroyos as sites for managed aquifer recharge through surface infiltration.The selected reaches were high-gradient (average 3.0–3.5 percent) braided channels filled with unconsolidated sand and gravel-sized deposits that were generally 30–50 feet thick. Saturation was not observed in the unconsolidated channel sands in four subsurface borings but was found at 7–60 feet below the contact between the unconsolidated channel sands and the bedrock. The poorly to well-cemented alluvial deposits that make up the bedrock underlying the unconsolidated channel material is the Tesuque Formation. The individual beds of the Tesuque Formation are reported to be highly heterogeneous and anisotropic, and the bedrock at the site was observed to have variable moisture and large changes in lithology. Surface electrical-resistivity geophysical survey methods showed a sharp contrast between the electrically resistive unconsolidated channel sands and the highly conductive bedrock; however, because of the high conductivity, the resistivity methods were not able to image the water table or preferential flow paths (if they existed) in the bedrock.Infiltration rates measured by double-ring and bulk infiltration tests on a variety of channel morphologies in the study reaches were extremely large (9.7–94.5 feet per day), indicating that the channels could potentially accommodate as much as 6.6 cubic feet per second of applied water without generating surface runoff out of the reach; however, the small volume

  7. Characterization of the interactions between endocrine disruptors and aquatic humic substances from tropical rivers

    Energy Technology Data Exchange (ETDEWEB)

    Botero, Wander G. [Universidade Federal de Alagoas (UFAL), Arapiraca, AL (Brazil); Oliveira, Luciana C. de [Universidade Federal de Sao Carlos (UFSCar), Sorocaba, SP (Brazil); Cunha, Bruno B.; Oliveira, Lilian K. de; Goveia, Danielle; Fraceto, Leonardo F.; Rosa, Andre Henrique, E-mail: ahrosa@sorocaba.unesp.b [UNESP, Sorocaba, SP (Brazil). Dept. de Engenharia do Meio Ambiente; Rocha, Julio Cesar [UNESP, Araraquara, SP (Brazil). Inst. de Quimica. Dept. de Quimica Analitica

    2011-07-01

    Interactions between two endocrine disruptors (ED) and aquatic humic substances (AHS) from tropical rivers were studied using an ultrafiltration system equipped with a 1 kDa cut-off cellulose membrane to separate free ED from the fraction bound in the AHS. Quantification of 17{alpha}-ethynylestradiol and bisphenol A was performed using gas chromatography-mass spectrometry (GC-MS). The times required for establishment of equilibrium between the AHS and the ED were ca. 30 min, and complexation capacities for 17{alpha}-ethynylestradiol and bisphenol A were 18.53 and 2.07 mg g{sup -1} TOC, respectively. The greater interaction of AHS with 17{alpha}-ethynylestradiol, compared to bisphenol A, was due to the presence of hydrogen in the structure of 17{alpha}-ethynylestradiol, which could interact with ionized oxygenated groups of the AHS. The results indicate that AHS can strongly influence the transport and reactivity of endocrine disruptors in aquatic systems. (author)

  8. Interactions between Rotavirus and Suwannee River Organic Matter: Aggregation, Deposition, and Adhesion Force Measurement

    KAUST Repository

    Gutierrez, Leonardo

    2012-08-21

    Interactions between rotavirus and Suwannee River natural organic matter (NOM) were studied by time-resolved dynamic light scattering, quartz crystal microbalance, and atomic force microscopy. In NOM-containing NaCl solutions of up to 600 mM, rotavirus suspension remained stable for over 4 h. Atomic force microscopy (AFM) measurement for interaction force decay length at different ionic strengths showed that nonelectrostatic repulsive forces were mainly responsible for eliminating aggregation in NaCl solutions. Aggregation rates of rotavirus in solutions containing 20 mg C/L increased with divalent cation concentration until reaching a critical coagulation concentration of 30 mM CaCl2 or 70 mM MgCl2. Deposition kinetics of rotavirus on NOM-coated silica surface was studied using quartz crystal microbalance. Experimental attachment efficiencies for rotavirus adsorption to NOM-coated surface in MgCl2 solution were lower than in CaCl2 solution at a given divalent cation concentration. Stronger adhesion force was measured for virus-virus and virus-NOM interactions in CaCl2 solution compared to those in MgCl2 or NaCl solutions at the same ionic strength. This study suggested that divalent cation complexation with carboxylate groups in NOM and on virus surface was an important mechanism in the deposition and aggregation kinetics of rotavirus. © 2012 American Chemical Society.

  9. Water winning in aquifers in the catchment area of the Elbe river. Task report no. 5: Radon applied for characterisation of geohydraulic processes; Wassergewinnung in Talgrundwasserleitern im Einzugsgebiet der Elbe. Teilbericht zum Thema Nr. 5: Radon zur Charakterisierung geohydraulischer Prozesse

    Energy Technology Data Exchange (ETDEWEB)

    Dehnert, J.; Nestler, W. [Hochschule fuer Technik und Wirtschaft, Dresden (Germany). Lab. fuer Geotechnik und Wasserwesen; Freyer, K.; Treutler, H.C. [UFZ - Umweltforschungszentrum Leipzig-Halle GmbH, Leipzig (Germany). Sektion Analytik

    1998-06-09

    The work performed has two objectives. The first is to test a new method for determination of optimal volumes of pumped groundwater samples at official sampling and measuring sites, in order to significantly enhance the level of representativity of groundwater samples. The second is to establish information about the required framework conditions which enable natural radon activity concentrations in river bank filtrates to be used for determination of residence times or infiltration velocities, respectively, of infiltration from surface waters to aquifers. Aspects of required equipment and instrumentation for both objectives are explained in the report. (orig./CB) [Deutsch] Mit dieser Arbeit werden zwei Ziele verfolgt. Mit dem neuen Verfahren zur Bestimmung optimaler Abpumpvolumen von Grundwassermessstellen soll die Repraesentativitaet von Grundwasserproben bei der Probennahme deutlich verbessert werden. Das zweite Ziel besteht in der Untersuchung der Voraussetzungen, unter denen die natuerliche Radonaktivitaetskonzentration des Uferfiltrats zur Bestimmung von Aufenthaltszeiten bzw. Infiltrationsgeschwindigkeiten von infiltriertem Oberflaechenwasser in Talgrundwasserleitern genutzt werden kann. Fuer beide Zielstellungen werden Moeglichkeiten fuer eine geraetetechnische Umsetzung aufgezeigt. (orig.)

  10. Examining the spatial and temporal variation of groundwater inflows to a valley-to-floodplain river using 222Rn, geochemistry and river discharge: the Ovens River, southeast Australia

    Science.gov (United States)

    Yu, M. C. L.; Cartwright, I.; Braden, J. L.; de Bree, S. T.

    2013-12-01

    Radon (222Rn) and major ion geochemistry were used to define and quantify the catchment-scale groundwater-surface water interactions along the Ovens River in the southeast Murray-Darling Basin, Victoria, Australia, between September 2009 and October 2011. The Ovens River is characterized by the transition from a single channel within a mountain valley in the upper catchment to a multi-channel meandering river on flat alluvial plains in the lower catchment. Overall, the Ovens River is dominated by gaining reaches, receiving groundwater from both alluvial and basement aquifers. The distribution of gaining and losing reaches is governed by catchment morphology and lithology. In the upper catchment, rapid groundwater recharge through the permeable aquifers increases the water table. The rising water table, referred to as hydraulic loading, increases the hydraulic head gradient toward the river and hence causes high baseflow to the river during wet (high flow) periods. In the lower catchment, lower rainfall and finer-gained sediments reduce the magnitude and variability of hydraulic gradient between the aquifer and the river, producing lower but more constant groundwater inflows. The water table in the lower reaches has a shallow gradient, and small changes in river height or groundwater level can result in fluctuating gaining and losing behaviour. The middle catchment represents a transition in river-aquifer interactions from the upper to the lower catchment. High baseflow in some parts of the middle and lower catchments is caused by groundwater flowing over basement highs. Mass balance calculations based on 222Rn activities indicate that groundwater inflows are 2 to 17% of total flow with higher inflows occurring during high flow periods. In comparison to 222Rn activities, estimates of groundwater inflows from Cl concentrations are higher by up to 2000% in the upper and middle catchment but lower by 50 to 100% in the lower catchment. The high baseflow estimates using

  11. Characterization of aquifer heterogeneity in a complex fluvial hydrogeologic system to evaluate migration in ground water

    International Nuclear Information System (INIS)

    Baker, F.G.; Pavlik, H.F.

    1990-01-01

    The hydrogeology and extent of ground water contamination were characterized at a site in northern California. Wood preserving compounds, primarily pentachlorophenol (PCP) and creosote, have been detected in the soil and ground water. A plume of dissolved PCP up to 1.5 miles long has been identified south of the plant. The aquifer consists of a complex multizonal system of permeable gravels and sands composed of units from four geologic formations deposited by the ancestral Feather River. Fluvial channel gravels form the principal aquifer zones and contain overbank clay and silt deposits which locally form clay lenses or more continuous aquitards. The geometric mean horizontal hydraulic conductivities for channel gravels range between 120 to 530 feet/day. Mean vertical aquitard hydraulic conductivity is 0.07 feet/day. Ground water flow is generally southward with a velocity ranging from 470 to 1000 feet/year. The spatial distribution of dissolved PCP in the aquifer documents the interactions between major permeable zones. Hydrostratigraphic evidence pointing to the separation of aquifer zones is supported by the major ion chemistry of ground water. The sodium and calcium-magnesium bicarbonate-rich water present in the upper aquifer zones is significantly different in chemical composition from the predominantly sodium chloride-rich water present in the deeper permeable zone. This indicates that hydrodynamic separation exists between the upper and lower zones of the aquifer, limiting the vertical movement of the PCP plume. A numerical ground water model, based on this conceptual hydrogeologic model, was developed to evaluate groundwater transport pathways and for use in the design of a ground water extraction and treatment system. (9 refs., 7 figs., tab.)

  12. Closed-form analytical solutions incorporating pumping and tidal effects in various coastal aquifer systems

    Science.gov (United States)

    Wang, Chaoyue; Li, Hailong; Wan, Li; Wang, Xusheng; Jiang, Xiaowei

    2014-07-01

    Pumping wells are common in coastal aquifers affected by tides. Here we present analytical solutions of groundwater table or head variations during a constant rate pumping from a single, fully-penetrating well in coastal aquifer systems comprising an unconfined aquifer, a confined aquifer and semi-permeable layer between them. The unconfined aquifer terminates at the coastline (or river bank) and the other two layers extend under tidal water (sea or tidal river) for a certain distance L. Analytical solutions are derived for 11 reasonable combinations of different situations of the L-value (zero, finite, and infinite), of the middle layer's permeability (semi-permeable and impermeable), of the boundary condition at the aquifer's submarine terminal (Dirichlet describing direct connection with seawater and no-flow describing the existence of an impermeable capping), and of the tidal water body (sea and tidal river). Solutions are discussed with application examples in fitting field observations and parameter estimations.

  13. Origin and residence time of water in the Lima Aquifer

    OpenAIRE

    Montoya, Modesto; Mamani, Enoc

    2014-01-01

    The 8 million inhabitants of the coastal city Lima are supplied with water from the Rimac and Chillon rivers and water wells in the Lima aquifer. The history of the Rimac River flow and static level of water in its wells have been correlated to calculate the residence time of water in the aquifer it is recharged by the Rimac River until it reaches a well located 12 km away in the Miraflores District near the sea. The relative abundance of H-2 and O-18 are used to identify the origins of the w...

  14. Northern tamarisk beetle (Diorhabda carinulata) and tamarisk (Tamarix spp.) interactions in the Colorado River basin

    Science.gov (United States)

    Nagler, Pamela L.; Nguyen, Uyen; Bateman, Heather L.; Jarchow, Christopher; Glenn, Edward P.; Waugh, William J.; van Riper, Charles

    2018-01-01

    Northern tamarisk beetles (Diorhabda carinulata) were released in the Upper Colorado River Basin in the United States in 2004–2007 to defoliate introduced tamarisk shrubs (Tamarix spp.) in the region’s riparian zones. The primary purpose was to control the invasive shrub and reduce evapotranspiration (ET) by tamarisk in an attempt to increase stream flows. We evaluated beetle–tamarisk interactions with MODIS and Landsat imagery on 13 river systems, with vegetation indices used as indicators of the extent of defoliation and ET. Beetles are widespread and exhibit a pattern of colonize–defoliate–emigrate, so that riparian zones contain a mosaic of completely defoliated, partially defoliated, and refoliated tamarisk stands. Based on satellite data and ET algorithms, mean ET before beetle release (2000–2006) was 416 mm/year compared to postrelease (2007–2015) ET of 355 mm/year (p<0.05) for a net reduction of 61 mm/year. This is lower than initial literature projections that ET would be reduced by 300–460 mm/year. Reasons for the lower-than-expected ET reductions are because baseline ET rates are lower than initially projected, and percentage ET reduction is low because tamarisk stands tend to regrow new leaves after defoliation and other plants help maintain canopy cover. Overall reductions in tamarisk green foliage during the study are 21%. However, ET in the Upper Basin has shown a steady decline since 2007 and equilibrium has not yet been reached. Defoliation is now proceeding from the Upper Basin into the Lower Basin at a rate of 40 km/year, much faster than initially projected.

  15. Characterizing groundwater/surface-water interactions in the interior of Jianghan Plain, central China

    Science.gov (United States)

    Du, Yao; Ma, Teng; Deng, Yamin; Shen, Shuai; Lu, Zongjie

    2018-01-01

    Quantifying groundwater/surface-water interactions is essential for managing water resources and revealing contaminant fate. There has been little concern on the exchange between streams and aquifers through an extensive aquitard thus far. In this study, hydrogeologic calculation and tritium modeling were jointly applied to characterize such interactions through an extensive aquitard in the interior of Jianghan Plain, an alluvial plain of Yangtze River, China. One groundwater simulation suggested that the lateral distance of influence from the river was about 1,000 m; vertical flow in the aquitard followed by lateral flow in the aquifer contributed significantly more ( 90%) to the aquifer head change near the river than lateral bank storage in the aquitard followed by infiltration. The hydrogeologic calculation produced vertical fluxes of the order 0.01 m/day both near and farther from the river, suggesting that similar shorter-lived (half-monthly) vertical fluxes occur between the river and aquitard near the river, and between the surface end members and aquitard farther from the river. Tritium simulation based on the OTIS model produced an average groundwater residence time of about 15 years near the river and a resulting vertical flux of the order 0.001 m/day. Another tritium simulation based on a dispersion model produced a vertical flux of the order 0.0001 m/day away from the river, coupled with an average residence time of around 90 years. These results suggest an order of magnitude difference for the longer-lived (decadal) vertical fluxes between surface waters and the aquifer near and away from the river.

  16. Simulation of ground-water flow and solute transport in the Glen Canyon aquifer, East-Central Utah

    Science.gov (United States)

    Freethey, Geoffrey W.; Stolp, Bernard J.

    2010-01-01

    The extraction of methane from coal beds in the Ferron coal trend in central Utah started in the mid-1980s. Beginning in 1994, water from the extraction process was pressure injected into the Glen Canyon aquifer. The lateral extent of the aquifer that could be affected by injection is about 7,600 square miles. To address regional-scale effects of injection over a decadal time frame, a conceptual model of ground-water movement and transport of dissolved solids was formulated. A numerical model that incorporates aquifer concepts was then constructed and used to simulate injection.The Glen Canyon aquifer within the study area is conceptualized in two parts—an active area of ground-water flow and solute transport that exists between recharge areas in the San Rafael Swell and Desert, Waterpocket Fold, and Henry Mountains and discharge locations along the Muddy, Dirty Devil, San Rafael, and Green Rivers. An area of little or negligible ground-water flow exists north of Price, Utah, and beneath the Wasatch Plateau. Pressurized injection of coal-bed methane production water occurs in this area where dissolved-solids concentrations can be more than 100,000 milligrams per liter. Injection has the potential to increase hydrologic interaction with the active flow area, where dissolved-solids concentrations are generally less than 3,000 milligrams per liter.Pressurized injection of coal-bed methane production water in 1994 initiated a net addition of flow and mass of solutes into the Glen Canyon aquifer. To better understand the regional scale hydrologic interaction between the two areas of the Glen Canyon aquifer, pressurized injection was numerically simulated. Data constraints precluded development of a fully calibrated simulation; instead, an uncalibrated model was constructed that is a plausible representation of the conceptual flow and solute-transport processes. The amount of injected water over the 36-year simulation period is about 25,000 acre-feet. As a result

  17. Ground Water movement in crystalline rock aquifers

    International Nuclear Information System (INIS)

    Serejo, A.N.C.; Freire, C.; Siqueira, H.B. de; Frischkorn, H.; Torquato, J.R.F.; Santiago, M.M.F.; Barbosa, P.C.

    1984-01-01

    Ground water movement studies were performed in crystalline rock aquifers from the upper Acarau River hydrographic basin, state of Ceara, Brazil. The studies included carbon-14, 18 O/ 16 O and tritium measurements as well as chemical analysis. A total of 35 wells were surveyed during drought seasons. Carbon-14 values displayed little variation which implied that the water use was adequate despite of the slower recharge conditions. Fairly constant isotopic 18 O/ 16 O ratio values in the wells and their similarity with rainwater values indicated that the recharge is done exclusively by pluvial waters. A decreasing tendency within the tritium concentration values were interpreted as a periodic rainwater renewal for these aquifers. The chemical analysis demonstrated that there is in fact no correlation between salinity and the time the water remains in the aquifer itself. (D.J.M.) [pt

  18. Slovenian test case Vrbanski Plato aquifer in the EU HORIZON 2020 FREEWAT project

    Directory of Open Access Journals (Sweden)

    Irena Kopač

    2017-09-01

    Full Text Available The Slovenian case study in the EU HORIZON 2020 FREEWAT project was Vrbanski Plato aquifer. Slovenia is divided into two river basin districts: the Danube and the North Adriatic. The Vrbanski Plato aquifer, which he presents both natural and artificial bank filtration from the river Drava, is a part of the Danube river basin district and is the most important water source for 14 municipalities in the northeastern part of Slovenia. We investigated the groundwatersurface water interaction between river Drava and the porous aquifer in the geological old riverbed and possible reduction of city impact. This site is the oldest managed artificial groundwater recharge with riverbank filtration and has more than thirty years of successful operation. It is something special, very abundant in a small space, independent of drought and climate changes, but vulnerable due to the impact of the city. Under the city there is watershed dividing, which is shifting with different water management condition and we would like to have the least possible impact of the city. For optimal water management we decided to use FREEWAT plug-in within QGIS platform. With new developed FREEWAT plug-in in project FREEWAT, we made steady-state and transient groundwater model for presenting this shift of the watershed dividing under the city and optimal water management for this area. The model was designed in a way that it identifies and describes all major aspects of the physical hydrogeological system and water management. During the running of a project, there was an accident with heating oil spillage in city area, right on the watershed dividing. So we oriented with the transient groundwater model as well on heating oil spillage and pumping with additional wells at the place of the accident to present successful rehabilitation and the importance of the managed groundwater recharge. Our experience with FREEWAT platform during the Vrbanski Plato aquifer case study was very

  19. Uranium series geochemistry in aquifers: quantification of transport mechanisms of uranium and daughter products: the chalk aquifer (Champagne, France); Desequilibres des series de l'uranium dans les aquiferes: quantification des mecanismes de transport de l'uranium et de ses descendants: cas de l'aquifere de la craie (Champagne, France)

    Energy Technology Data Exchange (ETDEWEB)

    Hubert, A

    2005-09-15

    With the increase of contaminant flux of radionuclides in surface environment (soil, river, aquifer...), there is a need to understand and model the processes that control the distribution of uranium and its daughter products during transport within aquifers. We have used U-series disequilibria as an analogue for the transport of uranium and its daughter products in aquifer to understand such mechanisms. The measurements of uranium ({sup 234}U et {sup 238}U), thorium ({sup 230}Th et {sup 232}Th), {sup 226}Ra and {sup 222}Rn isotopes in the solid and liquid phases of the chalk aquifer in Champagne (East of France) allows us to understand the processes responsible for fractionation within the uranium decay chain. Fractionations are induced by physical and chemical properties of the elements (leaching, adsorption) but also by radioactive properties (recoil effect during {alpha}-decay). For the first time a comprehensive sampling of the solid phase has been performed, allowing quantifying mechanisms responsible for the long term evolution of the aquifer. A non steady state 1D model has been developed which takes into account leaching, adsorption processes as well as radioactive filiation and {alpha}-recoil effect. Retardation coefficients have been calculated for uranium, thorium and radium. The aquifer is characterised by a double porosity, and the contribution of fracture and matrix porosity on the water/rock interaction processes has been estimated. (author)

  20. Application of Near-Surface Remote Sensing and computer algorithms in evaluating impacts of agroecosystem management on Zea mays (corn) phenological development in the Platte River - High Plains Aquifer Long Term Agroecosystem Research Network field sites.

    Science.gov (United States)

    Okalebo, J. A.; Das Choudhury, S.; Awada, T.; Suyker, A.; LeBauer, D.; Newcomb, M.; Ward, R.

    2017-12-01

    The Long-term Agroecosystem Research (LTAR) network is a USDA-ARS effort that focuses on conducting research that addresses current and emerging issues in agriculture related to sustainability and profitability of agroecosystems in the face of climate change and population growth. There are 18 sites across the USA covering key agricultural production regions. In Nebraska, a partnership between the University of Nebraska - Lincoln and ARD/USDA resulted in the establishment of the Platte River - High Plains Aquifer LTAR site in 2014. The site conducts research to sustain multiple ecosystem services focusing specifically on Nebraska's main agronomic production agroecosystems that comprise of abundant corn, soybeans, managed grasslands and beef production. As part of the national LTAR network, PR-HPA participates and contributes near-surface remotely sensed imagery of corn, soybean and grassland canopy phenology to the PhenoCam Network through high-resolution digital cameras. This poster highlights the application, advantages and usefulness of near-surface remotely sensed imagery in agroecosystem studies and management. It demonstrates how both Infrared and Red-Green-Blue imagery may be applied to monitor phenological events as well as crop abiotic stresses. Computer-based algorithms and analytic techniques proved very instrumental in revealing crop phenological changes such as green-up and tasseling in corn. This poster also reports the suitability and applicability of corn-derived computer based algorithms for evaluating phenological development of sorghum since both crops have similarities in their phenology; with sorghum panicles being similar to corn tassels. This later assessment was carried out using a sorghum dataset obtained from the Transportation Energy Resources from Renewable Agriculture Phenotyping Reference Platform project, Maricopa Agricultural Center, Arizona.

  1. Water quality responses to the interaction between surface water and groundwater along the Songhua River, NE China

    Science.gov (United States)

    Teng, Yanguo; Hu, Bin; Zheng, Jieqiong; Wang, Jinsheng; Zhai, Yuanzheng; Zhu, Chen

    2018-03-01

    Investigation of surface water and groundwater interaction (SW-GW interaction) provides basic information for regional water-resource protection, management, and development. In this survey of a 10-km-wide area along both sides of the Songhua River, northeast China, the hydrogeochemical responses to different SW-GW interactions were studied. Three types of SW-GW interactions were identified—"recharge", "discharge", and "flow-through"—according to the hydraulic connection between the surface water and groundwater. The single factor index, principal component analysis, and hierarchical cluster analysis of the hydrogeochemistry and pollutant data illuminated the hydrogeochemical response to the various SW-GW interactions. Clear SW-GW interactions along the Songhua River were revealed: (1) upstream in the study area, groundwater usually discharges into the surface water, (2) groundwater is recharged by surface water downstream, and (3) discharge and flow-through coexist in between. Statistical analysis indicated that the degree of hydrogeochemical response in different types of hydraulic connection varied, being clear in recharge and flow-through modes, and less obvious in discharge mode. During the interaction process, dilution, adsorption, redox reactions, nitrification, denitrification, and biodegradation contributed to the pollutant concentration and affected hydrogeochemical response in the hyporheic zone.

  2. Geomorphic Controls on Aquifer Geometry in Northwestern India

    Science.gov (United States)

    van Dijk, W. M.; Densmore, A. L.; Sinha, R.; Gupta, S.; Mason, P. J.; Singh, A.; Joshi, S. K.; Nayak, N.; Kumar, M.; Shekhar, S.

    2014-12-01

    The Indo-Gangetic foreland basin suffers from one of the highest rates of groundwater extraction in the world, especially in the Indian states of Punjab, Haryana and Rajasthan. To understand the effects of this extraction on ground water levels, we must first understand the geometry and sedimentary architecture of the aquifer system, which in turn depend upon its geomorphic setting. We use satellite images and digital elevation models to map the geomorphology of the Sutlej and Yamuna river systems, while aquifer geometry is assessed using ~250 wells that extend to ~300 m depth in Punjab and Haryana. The Sutlej and Yamuna rivers have deposited large sedimentary fans at their outlets. Elongate downslope ridges on the fan surfaces form distributary networks that radiate from the Sutlej and Yamuna fan apices, and we interpret these ridges as paleochannel deposits associated with discrete fan lobes. Paleochannels picked out by soil moisture variations illustrate a complex late Quaternary history of channel avulsion and incision, probably associated with variations in monsoon intensity. Aquifer bodies on the Sutlej and Yamuna fans have a median thickness of 7 and 6 m, respectively, and follow a heavy-tailed distribution, probably because of stacked sand bodies. The percentage of aquifer material in individual lithologs decreases downstream, although the exponent on the thickness distribution remains the same, indicating that aquifer bodies decrease in number down fan but do not thin appreciably. Critically, the interfan area between the Sutlej and Yamuna fans has thinner aquifers and a lower proportion of aquifer material, despite its proximal location. Our data show that the Sutlej and Yamuna fan systems form the major aquifer systems in this area, and that their geomorphic setting therefore provides a first-order control on aquifer distribution and geometry. The large spatial heterogeneity of the system must be considered in any future aquifer management scheme.

  3. Wild Steelhead and introduced spring Chinook Salmon in the Wind River, Washington: Overlapping populations and interactions

    Science.gov (United States)

    Jezorek, I.G.; Connolly, P.J.

    2010-01-01

    We investigated interactions of introduced juvenile spring Chinook salmon Oncorhynchus tshawytscha with wild juvenile steelhead O. mykiss in the upper Wind River watershed (rkm 24.6 to rkm 43.8), Washington. Our objective was to determine if the presence of introduced spring Chinook salmon influenced populations of wild juvenile steelhead and if other biotic or abiotic factors influenced distribution and populations of these species. We snorkeled to assess distribution and abundance in one to six stream reaches per year during 2001 through 2007. Juvenile steelhead were found in each sampled reach each year, but juvenile Chinook salmon were not. The upstream extent of distribution of juvenile Chinook salmon varied from rkm 29.7 to 42.5. Our analyses suggest that juvenile Chinook salmon distribution was much influenced by flow during the spawning season. Low flow appeared to limit access of escaped adult Chinook salmon to upper stream reaches. Abundance of juvenile Chinook salmon was also influenced by base flow during the previous year, with base flow occurring post spawn in late August or early September. There were no relationships between juvenile Chinook salmon abundance and number of Chinook salmon spawners, magnitude of winter flow that might scour redds, or abundance of juvenile steelhead. Abundance of age-0 steelhead was influenced primarily by the number of steelhead spawners the previous year, and abundance of age-1 steelhead was influenced primarily by abundance of age-0 steelhead the previous year. Juvenile steelhead abundance did not show a relationship with base or peak flows, nor with number of escaped Chinook salmon adults during the previous year. We did not detect a negative influence of the relatively low abundance of progeny of escaped Chinook salmon on juvenile steelhead abundance. This low abundance of juvenile Chinook salmon was persistent throughout our study and is likely a result of hatchery management and habitat conditions. Should one or

  4. The socio-hydrologic evolution of human-flood interactions on the Charles and Mystic River, eastern Massachusetts, USA.

    Science.gov (United States)

    Mertz, Z.

    2015-12-01

    Socio-hydrology is an emerging subdiscipline for identifying the emergent properties of human-flood interactions. The Charles and the Mystic Rivers, in eastern Massachusetts, have been the subject of such interactions for hundreds of years. Over time, human dependency and settlement have altered the natural conditions of the rivers, and changed the potential for flood occurrence and property damage. As a result, flood management strategies have been enacted to counter this potential. Before we can assess how human vulnerability and actions related to river flooding will change under future climate conditions, we must first document the evolution of flooding and flood management and understand the motivations and thresholds of response that describe how the system has evolved in the past. We have mined historical data from traditional and non-traditional sources and have developed "mental models" from in-depth interviews of key personnel. We will present the socio-hydrological history of the Charles and Mystic Rivers and recommend how this information can inform future flood management strategies in the face of climate change.

  5. Impact of hydrological alterations on river-groundwater exchange and water quality in a semi-arid area: Nueces River, Texas.

    Science.gov (United States)

    Murgulet, Dorina; Murgulet, Valeriu; Spalt, Nicholas; Douglas, Audrey; Hay, Richard G

    2016-12-01

    There is a lack of understanding and methods for assessing the effects of anthropogenic disruptions, (i.e. river fragmentation due to dam construction) on the extent and degree of groundwater-surface water interaction and geochemical processes affecting the quality of water in semi-arid, coastal catchments. This study applied a novel combination of electrical resistivity tomography (ERT) and elemental and isotope geochemistry in a coastal river disturbed by extended drought and periodic flooding due to the operation of multiple dams. Geochemical analyses show that the saltwater barrier causes an increase in salinity in surface water in the downstream river as a result of limited freshwater inflows, strong evaporation effects on shallow groundwater and mostly stagnant river water, and is not due to saltwater intrusion by tidal flooding. Discharge from bank storage is dominant (~84%) in the downstream fragment and its contribution could increase salinity levels within the hyporheic zone and surface water. When surface water levels go up due to upstream freshwater releases the river temporarily displaces high salinity water trapped in the hyporheic zone to the underlying aquifer. Geochemical modeling shows a higher contribution of distant and deeper groundwater (~40%) in the upstream river and lower discharge from bank storage (~13%) through the hyporheic zone. Recharge from bank storage is a source of high salt to both upstream and downstream portions of the river but its contribution is higher below the dam. Continuous ERT imaging of the river bed complements geochemistry findings and indicate that while lithologically similar, downstream of the dam, the shallow aquifer is affected by salinization while fresher water saturates the aquifer in the upstream fragment. The relative contribution of flows (i.e. surface water releases or groundwater discharge) as related to the river fragmentation control changes of streamwater chemistry and likely impact the interpretation

  6. Application of multiple-isotope and groundwater-age data to identify factors affecting the extent of denitrification in a shallow aquifer near a river in South Korea

    Science.gov (United States)

    Kaown, Dugin; Koh, Eun-Hee; Mayer, Bernhard; Kim, Heejung; Park, Dong Kyu; Park, Byeong-Hak; Lee, Kang-Kun

    2018-01-01

    The extent of denitrification in a small agricultural area near a river in Yangpyeong, South Korea, was determined using multiple isotopes, groundwater age, and physicochemical data for groundwater. The shallow groundwater at one monitoring site had high concentrations of NO3-N (74-83 mg L-1). The δ15N-NO3 values for groundwater in the study area ranged between +9.1 and +24.6‰ in June 2014 and +12.2 to +21.6‰ in October 2014. High δ15N-NO3 values (+10.7 to +12.5‰) in both sampling periods indicated that the high concentrations of nitrate in the groundwater originated from application of organic fertilizers and manure. In the northern part of the study area, some groundwater samples showed elevated δ15N-NO3 and δ18O-NO3 values, which suggest that nitrate was removed from the groundwater via denitrification, with N isotope enrichment factors ranging between -4.8 and -7.9‰ and O isotope enrichment factors varying between -3.8 and -4.9‰. Similar δD and δ18O values of the surface water and groundwater in the south appear to indicate that groundwater in that area was affected by surface-water infiltration. The mean residence times (MRTs) of groundwater showed younger ages in the south (10-20 years) than in the north (20-30 years). Hence, it was concluded that denitrification processes under anaerobic conditions with longer groundwater MRT in the northern part of the study area removed considerable amounts of nitrate. This study demonstrates that multi-isotope data combined with physicochemical data and age-dating information can be effectively applied to characterize nitrate contaminant sources and attenuation processes.

  7. Ground-water quality of the surficial aquifer system and the upper Floridan Aquifer, Ocala National Forest and Lake County, Florida, 1990-99

    Science.gov (United States)

    Adamski, J.C.; Knowles, Leel

    2001-01-01

    Data from 217 ground-water samples were statistically analyzed to assess the water quality of the surficial aquifer system and Upper Floridan aquifer in the Ocala National Forest and Lake County, Florida. Samples were collected from 49 wells tapping the surficial aquifer system, 141 wells tapping the Upper Floridan aquifer, and from 27 springs that discharge water from the Upper Floridan aquifer. A total of 136 samples was collected by the U.S. Geological Survey from 1995 through 1999. These data were supplemented with 81 samples collected by the St. Johns River Water Management District and Lake County Water Resources Management from 1990 through 1998. In general, the surficial aquifer system has low concentrations of total dissolved solids (median was 41 milligrams per liter) and major ions. Water quality of the surficial aquifer system, however, is not homogeneous throughout the study area. Concentrations of total dissolved solids, many major ions, and nutrients are greater in samples from Lake County outside the Ocala National Forest than in samples from within the Forest. These results indicate that the surficial aquifer system in Lake County outside the Ocala National Forest probably is being affected by agricultural and (or) urban land-use practices. High concentrations of dissolved oxygen (less than 0.1 to 8.2 milligrams per liter) in the surficial aquifer system underlying the Ocala National Forest indicate that the aquifer is readily recharged by precipitation and is susceptible to surface contamination. Concentrations of total dissolved solids were significantly greater in the Upper Floridan aquifer (median was 182 milligrams per liter) than in the surficial aquifer system. In general, water quality of the Upper Floridan aquifer was homogeneous, primarily being a calcium or calciummagnesium- bicarbonate water type. Near the St. Johns River, the water type of the Upper Floridan aquifer is sodium-chloride, corresponding to an increase in total dissolved

  8. Nonlinear interactions between the Amazon River basin and the Tropical North Atlantic at interannual timescales

    Science.gov (United States)

    Builes-Jaramillo, Alejandro; Marwan, Norbert; Poveda, Germán; Kurths, Jürgen

    2018-04-01

    We study the physical processes involved in the potential influence of Amazon (AM) hydroclimatology over the Tropical North Atlantic (TNA) Sea Surface Temperatures (SST) at interannual timescales, by analyzing time series of the precipitation index (P-E) over AM, as well as the surface atmospheric pressure gradient between both regions, and TNA SSTs. We use a recurrence joint probability based analysis that accounts for the lagged nonlinear dependency between time series, which also allows quantifying the statistical significance, based on a twin surrogates technique of the recurrence analysis. By means of such nonlinear dependence analysis we find that at interannual timescales AM hydrology influences future states of the TNA SSTs from 0 to 2 months later with a 90-95% statistical confidence. It also unveils the existence of two-way feedback mechanisms between the variables involved in the processes: (1) precipitation over AM leads the atmospheric pressure gradient between TNA and AM from 0 to 2 month lags, (2) the pressure gradient leads the trade zonal winds over the TNA from 0 to 3 months and from 7 to 12 months, (3) the zonal winds lead the SSTs from 0 to 3 months, and (4) the SSTs lead precipitation over AM by 1 month lag. The analyses were made for time series spanning from 1979 to 2008, and for extreme precipitation events in the AM during the years 1999, 2005, 2009 and 2010. We also evaluated the monthly mean conditions of the relevant variables during the extreme AM droughts of 1963, 1980, 1983, 1997, 1998, 2005, and 2010, and also during the floods of 1989, 1999, and 2009. Our results confirm that the Amazon River basin acts as a land surface-atmosphere bridge that links the Tropical Pacific and TNA SSTs at interannual timescales. The identified mutual interactions between TNA and AM are of paramount importance for a deeper understanding of AM hydroclimatology but also of a suite of oceanic and atmospheric phenomena over the TNA, including recently

  9. Interactions between fauna and environment in recent alluvial soils (Dunajec River, SE Poland)

    Science.gov (United States)

    Mikuś, Paweł; Uchman, Alfred

    2017-04-01

    Recent riverine system is a particular place for interactions between fauna and the deposited sediments containing young and old alluvial soils. It is characterized by large energy gradients in relatively short time, which forces special adaptations of burrowing animals recorded in bioturbation structures. Predators produce mainly shelter burrows (interpreted as domichnia), and saprofags, especially earthworms, produce locomotion and feeding structures (pascichnia). Such structures have been studied in non- or poorly vegetated, sandy or muddy Holocene alluvia in the lower reach of the Dunajec River flowing through the Carpathian Foredeep in SE Poland. The observed burrows are mostly produced by a variety of organisms, including the European mole (Talpa europaea), common earthworm (Lumbricus terrestris), ground beetles (Carabidae), solitary bees (Ammophila), red fox (Vulpes vulpes), European beaver (Castor fiber), shrews (Soricidae), European otter (Lutra lutra), several species of mice (Muridae), voles (Myodae, Microtae), and the swallow sand martin (Riparia riparia). Burrows of a few species of ground beetles have been subjected to more detailed studies. Fertile deposits of older (early to middle Holocene) terraces, formed with many long-term interruptions in sedimentation processes, have a well-developed soil levels, more vulnerable to burrowing than recently deposited sediments. The terraces contain layers of sands and muds, which primary sedimentary structures and layer boundaries are completely or partly disturbed by bioturbation. Organic-rich muds have been moved up and down and mixed with sand. Moreover, sediments have been leached into open burrows during floods or rainfalls. In the natural levee sediments, mostly fine to medium sands, are horizontally burrowed, foremost by earthworms (Lumbricidae). Vertical, long (over 2 m deep) burrows of larger earthworms cross cut the natural levee sediments and enter buried soils. They were formed during a long period

  10. Hydrochemical study of Drean–Annaba aquifer system (NE Algeria

    Directory of Open Access Journals (Sweden)

    Sayad Lamine

    2017-09-01

    Full Text Available Water quality is subject to frequent changes in the Drean-Annaba alluvium aquifer. Water-rock interaction can not be the only process that produces the observed modification, but dryness that the country knew during the last two decades has highly contributed to the water quality changes. During this period, irregularities in the distribution of rainfalls, in time and space, have been observed. As a result, a periodicity in hydrochemical changes in water of wells and rivers is noticed. Statistical, the principals components analysis (PCA tools and Tickel diagram have been used to show, through chemical presentation, these effects. The results show, indeed, seasonal changes of water quality for the period 1999-2000. From a cationic point of view, a competition between alkaline and alkaline earths is shown. On the other hand, from an anionic point of view, there is a transition from chlorides to sulphates and may be to bicarbonates. The present work was carried out in a relatively small area and this was useful to show the relationship that existed between dryness and water quality of both the aquifer system and surface water.

  11. Dynamic Modeling and Grid Interaction of a Tidal and River Generator

    Energy Technology Data Exchange (ETDEWEB)

    Muljadi, Eduard; Gevorgian, Vahan; Donegan, James; Marnagh, Cian; McEntee, Jarlath

    2017-07-13

    This presentation provides a high-level overview of the deployment of a river generator installed in a small system. The turbine dynamics of a river generator, electrical generator, and power converter are modeled in detail. Various simulations can be exercised, and the impact of different control algorithms, failures of power switches, and corresponding impacts can be examined.

  12. Transient Inverse Calibration of Site-Wide Groundwater Model to Hanford Operational Impacts from 1943 to 1996-Alternative Conceptual Model Considering Interaction with Uppermost Basalt Confined Aquifer; FINAL

    International Nuclear Information System (INIS)

    Vermeul, Vince R; Cole, Charles R; Bergeron, Marcel P; Thorne, Paul D; Wurstner, Signe K

    2001-01-01

    The baseline three-dimensional transient inverse model for the estimation of site-wide scale flow parameters, including their uncertainties, using data on the transient behavior of the unconfined aquifer system over the entire historical period of Hanford operations, has been modified to account for the effects of basalt intercommunication between the Hanford unconfined aquifer and the underlying upper basalt confined aquifer. Both the baseline and alternative conceptual models (ACM-1) considered only the groundwater flow component and corresponding observational data in the 3-Dl transient inverse calibration efforts. Subsequent efforts will examine both groundwater flow and transport. Comparisons of goodness of fit measures and parameter estimation results for the ACM-1 transient inverse calibrated model with those from previous site-wide groundwater modeling efforts illustrate that the new 3-D transient inverse model approach will strengthen the technical defensibility of the final model(s) and provide the ability to incorporate uncertainty in predictions related to both conceptual model and parameter uncertainty

  13. The use of computer-assisted interactive videodisc training in reactor operations at the Savannah River site

    International Nuclear Information System (INIS)

    Shiplett, D.W.

    1990-01-01

    This presentation discussed the use of computer aided training at Savannah River Site using a computer-assisted interactive videodisc system. This system was used in situations where there was a high frequency of training required, where there were a large number of people to be trained and where there was a rigid work schedule. The system was used to support classroom training to emphasize major points, display graphics of flowpaths, for simulations, and video of actual equipment

  14. Experimental investigation of CO2-brine-rock interactions at elevated temperature and pressure: Implications for CO2 sequestration in deep-saline aquifers

    Science.gov (United States)

    Rosenbauer, R.J.; Koksalan, T.; Palandri, J.L.

    2005-01-01

    Deep-saline aquifers are potential repositories for excess CO2, currently being emitted to the atmosphere from anthropogenic activities, but the reactivity of supercritical CO2 with host aquifer fluids and formation minerals needs to be understood. Experiments reacting supercritical CO2 with natural and synthetic brines in the presence and absence of limestone and plagioclase-rich arkosic sandstone showed that the reaction of CO2-saturated brine with limestone results in compositional, mineralogical, and porosity changes in the aquifer fluid and rock that are dependent on initial brine composition, especially dissolved calcium and sulfate. Experiments reacting CO2-saturated, low-sulfate brine with limestone dissolved 10% of the original calcite and increased rock porosity by 2.6%. Experiments reacting high-sulfate brine with limestone, both in the presence and absence of supercritical CO2, were characterized by the precipitation of anhydrite, dolomitization of the limestone, and a final decrease in porosity of 4.5%. However, based on favorable initial porosity changes of about 15% due to the dissolution of calcite, the combination of CO2 co-injection with other mitigation strategies might help alleviate some of the well-bore scale and formation-plugging problems near the injection zone of a brine disposal well in Paradox Valley, Colorado, as well as provide a repository for CO2. Experiments showed that the solubility of CO2 is enhanced in brine in the presence of limestone by 9% at 25 ??C and 6% at 120 ??C and 200 bar relative to the brine itself. The solubility of CO2 is enhanced also in brine in the presence of arkosic sandstone by 5% at 120 ??C and 300 bar. The storage of CO 2 in limestone aquifers is limited to only ionic and hydraulic trapping. However, brine reacted with supercritical CO2 and arkose yielded fixation and sequestration of CO2 in carbonate mineral phases. Brine desiccation was observed in all experiments containing a discrete CO2 phase

  15. Fine Sediment Input and Benthic Fauna Interactions at the Confluence of Two Large Rivers

    International Nuclear Information System (INIS)

    Blettler, M. C. M.; Amsler, M. L.; Ezcurra De Drago, I.; Drago, E.; Paira, A.; Espinola, L. A.; Eberle, E.; Szupiany, R.

    2016-01-01

    Several studies suggest that invertebrate abundance and richness are disrupted and reset at confluences. Thus, junctions contribute disproportionately to the overall aquatic biodiversity of the river. In general terms, authors have reported high abundance and diversity due to the major physical heterogeneity at junctions. However, data are still scarce and uncertainties are plentiful. The impact of a great input of fine sediments on the distribution patterns of benthic invertebrates at a river confluence was quantitatively analyzed herein. The junction of the subtropical Bermejo River (high suspended sediment load) with the large Paraguay River is the selected study area to achieve this aim. While diversity increased slightly downstream the junction (from 0.21 to 0.36), density and richness of the macro invertebrate assemblage significantly diminished downstream the confluence (from 29050 to 410 ind/m2; p< 0.05) due to the input of fine sediment from the Bermejo River (mean fine sediment increased downstream from 6.3 to 10.2 mg/L), causing a negatively impact on invertebrate assemblage. This study highlights the ecological importance of the sediment input effects on benthic invertebrates, a topic still poorly explored in river ecology. It is speculated that the spatial extent of the impact would be dependent upon the hydrological and sedimentological context, highly unequal between both rivers. New hypotheses should be tested through new studies considering different hydrological stages.

  16. Riparian vegetation interacting with river morphology : modelling long-term ecosystem responses to invasive species, climate change, dams and river restoration

    NARCIS (Netherlands)

    van Oorschot, M.

    2017-01-01

    River systems are amongst the most dynamic and productive ecosystems in the world and provide habitats for numerous fluvial species. River flow and river shape determine the conditions that affect plant growth and survival. In turn, riparian plants can actively influence river flow and sedimentation

  17. Recharge sources and geochemical evolution of groundwater in the Quaternary aquifer at Atfih area, the northeastern Nile Valley, Egypt

    Science.gov (United States)

    El-Sayed, Salah Abdelwahab; Morsy, Samah M.; Zakaria, Khalid M.

    2018-06-01

    This study addresses the topic of recharge sources and evolution of groundwater in the Atfih area situated in the northeastern part of the Nile Valley, Egypt. Inventory of water wells and collection of groundwater and surface water samples have been achieved. Water samples are analyzed for major ions according to the American Society for Testing and Materials and for the environmental isotopes analysis (oxygen-18 and deuterium) by using a Triple Liquid Isotopic Water Analyzer (Los Gatos). The groundwater is available from the Quaternary aquifer formed mainly of graded sand and gravel interbedded with clay lenses. The hydrogeologic, hydrogeochemical and isotopic investigations indicate the hydrodynamic nature of the aquifer, where different flow paths, recharge sources and evolution mechanisms are distinguished. The directions of groundwater flow are from E, W and S directions suggesting the contribution from Nile River, the Eocene aquifer and the Nile basin, respectively. The groundwater altitudes range from 13 m (MSL) to 44 m (MSL). The hydraulic gradient varies between 0.025 and 0.0015. The groundwater is alkaline (pH > 7) and has salinity ranging from fresh to brackish water (TDS between 528 mg/l and 6070 mg/l). The observed wide range in the ionic composition and water types reflects the effect of different environmental and geological conditions through which the water has flowed. The isotopic compositions of groundwater samples vary between -14.13‰ and +23.56 for δD and between - 2.91‰ and +3.10 for δ18O. The isotopic data indicates that the Quaternary aquifer receive recharge from different sources including the Recent Nile water, surplus irrigation water, old Nile water before the construction of Aswan High Dam, surface runoff of local rains and Eocene aquifer. Evaporation, water rock interaction and mixing between different types of waters are the main processes in the groundwater evolution. Major suggestions are presented to develop the aquifer

  18. Interaction of polybrominated diphenyl ethers (PBDEs) with anaerobic mixed bacterial cultures isolated from river sediment

    Energy Technology Data Exchange (ETDEWEB)

    Yen, J H; Liao, W C; Chen, W C [Department of Agricultural Chemistry, National Taiwan University, 1, Sec. 4, Roosevelt Road, Taipei 10617, Taiwan (China); Wang, Y.S., E-mail: yswang@ntu.edu.tw [Department of Agricultural Chemistry, National Taiwan University, 1, Sec. 4, Roosevelt Road, Taipei 10617, Taiwan (China)

    2009-06-15

    The degradation of flame retardant polybrominated diphenyl ethers (PBDE), including tetra-brominated diphenyl ether (BDE-47), penta-brominated diphenyl ether (BDE-99 and -100), and hexa-brominated diphenyl ether (BDE-153 and -154), by anaerobic bacterial mixed cultures isolated from river sediment was investigated. The effects of PBDEs on changes of anaerobic bacterial community in sediment culture were also studied. Sediments were collected from Er-Jen River and Nan-Kan River basins, which were both heavily polluted rivers in Taiwan, and bacteria from the sediment samples were enriched before the experiment was conducted. Into the anaerobic bacterial mixed cultures, 0.1 {mu}g/mL of PBDEs was added followed by incubation under 30 deg. C for 70 days. Residues of PBDE were determined by gas chromatography with electron capture detector (GC-ECD), and the changes of bacterial community were analyzed by denaturing gradient gel electrophoresis (DGGE). Less than 20% of PBDEs were degraded after 70 days of incubation in all samples except for BDE-47 from the Nan-Kan River sediment. In that culture, BDE-47 was found to have notably degraded. In particular, after 42 days of incubation; BDE-47 was degraded, suddenly and sharply, to a negligible level on Day 70, and the result was confirmed by a repeated experiment. An interesting result was that although BDE-47 was degraded fast in the Nan-Kan River sediment, the bacterial communities did not shift significantly as we had speculated at Day 70. From UPGMA dendrograms, PBDEs changed the composition of bacterial communities, and the extents varied with the variety of PBDE congeners. By the amendment with BDE-153 or -154, bacterial communities would be changed immediately and irreversibly throughout the rest of the incubation period. No significant difference in degradation of PBDEs was observed between sediment bacteria from Er-Jen River and Nan-Kan River. However, the results verified the persistence of PBDEs in the environment.

  19. Interaction of polybrominated diphenyl ethers (PBDEs) with anaerobic mixed bacterial cultures isolated from river sediment

    International Nuclear Information System (INIS)

    Yen, J.H.; Liao, W.C.; Chen, W.C.; Wang, Y.S.

    2009-01-01

    The degradation of flame retardant polybrominated diphenyl ethers (PBDE), including tetra-brominated diphenyl ether (BDE-47), penta-brominated diphenyl ether (BDE-99 and -100), and hexa-brominated diphenyl ether (BDE-153 and -154), by anaerobic bacterial mixed cultures isolated from river sediment was investigated. The effects of PBDEs on changes of anaerobic bacterial community in sediment culture were also studied. Sediments were collected from Er-Jen River and Nan-Kan River basins, which were both heavily polluted rivers in Taiwan, and bacteria from the sediment samples were enriched before the experiment was conducted. Into the anaerobic bacterial mixed cultures, 0.1 μg/mL of PBDEs was added followed by incubation under 30 deg. C for 70 days. Residues of PBDE were determined by gas chromatography with electron capture detector (GC-ECD), and the changes of bacterial community were analyzed by denaturing gradient gel electrophoresis (DGGE). Less than 20% of PBDEs were degraded after 70 days of incubation in all samples except for BDE-47 from the Nan-Kan River sediment. In that culture, BDE-47 was found to have notably degraded. In particular, after 42 days of incubation; BDE-47 was degraded, suddenly and sharply, to a negligible level on Day 70, and the result was confirmed by a repeated experiment. An interesting result was that although BDE-47 was degraded fast in the Nan-Kan River sediment, the bacterial communities did not shift significantly as we had speculated at Day 70. From UPGMA dendrograms, PBDEs changed the composition of bacterial communities, and the extents varied with the variety of PBDE congeners. By the amendment with BDE-153 or -154, bacterial communities would be changed immediately and irreversibly throughout the rest of the incubation period. No significant difference in degradation of PBDEs was observed between sediment bacteria from Er-Jen River and Nan-Kan River. However, the results verified the persistence of PBDEs in the environment.

  20. Interactions between brown bears and chum salmon at McNeil River, Alaska

    Science.gov (United States)

    Peirce, Joshua M.; Otis, Edward O.; Wipfli, Mark S.; Follmann, Erich H.

    2013-01-01

    Predation on returning runs of adult salmon (Oncorhynchus spp.) can have a large influence on their spawning success. At McNeil River State Game Sanctuary (MRSGS), Alaska, brown bears (Ursus arctos) congregate in high numbers annually along the lower McNeil River to prey upon returning adult chum salmon (O. keta). Low chum salmon escapements into McNeil River since the late 1990s have been proposed as a potential factor contributing to concurrent declines in bear numbers. The objective of this study was to determine the extent of bear predation on chum salmon in McNeil River, especially on pre-spawning fish, and use those data to adjust the escapement goal for the river. In 2005 and 2006, 105 chum salmon were radiotagged at the river mouth and tracked to determine cause and location of death. Below the falls, predators consumed 99% of tagged fish, killing 59% of them before they spawned. Subsequently, the escapement goal was nearly doubled to account for this pre-spawning mortality and to ensure enough salmon to sustain both predators and prey. This approach to integrated fish and wildlife management at MRSGS can serve as a model for other systems where current salmon escapement goals may not account for pre-spawning mortality.

  1. Aquifer Sampling Tube Completion Report: 100 Area and Hanford Townsite Shorelines

    International Nuclear Information System (INIS)

    Peterson, R.E.; Borghese, J.V.; Erb, D.B.

    1998-02-01

    Groundwater contamination is known or suspected along the Hanford Site shoreline of the Columbia River adjacent to the retired reactor areas. Along the shoreline away from the reactor areas, where contamination is presumed to be absent, monitoring sites are frequently widely spaced or unavailable to confirm the presumption. Previous characterizations of contamination near the river have relied on data from a limited number of near-river wells, contaminant plume migration predictions, and river bank seepage sampling to anticipate shoreline conditions. In recent years, new methods have been developed to obtain groundwater samples from the aquifer near the groundwater/river water interface. These methods include using (1) divers to obtain samples of pore water from riverbed sediment and (2) sampling tubes that are driven into the aquifer at the shoreline. The latter method also permits sampling the aquifer at multiple depths, which helps to determine the thickness of the potentially contaminated groundwater layer that discharges into the river

  2. Implications of Kali–Hindon inter-stream aquifer water balance for ...

    Indian Academy of Sciences (India)

    evaporation from the water table, discharge from the aquifer to rivers and horizontal subsurface outflows were also ... and their future supply potential in order to predict possible conflicts ..... losses via evaporation losses and horizontal subsur-.

  3. Characterizing aquifer hydrogeology and anthropogenic chemical influences on groundwater near the Idaho Chemical Processing Plant, Idaho National Engineering Laboratory, Idaho

    International Nuclear Information System (INIS)

    Fromm, J.M.

    1995-01-01

    A conceptual model of the Eastern Snake River Plain aquifer in the vicinity of monitoring well USGS-44, downgradient of the Idaho Chemical Processing Plant (ICPP) on the Idaho National Engineering Laboratory (INEL), was developed by synthesis and comparison of previous work (40 years) and new investigations into local natural hydrogeological conditions and anthropogenic influences. Quantitative tests of the model, and other recommendations are suggested. The ICPP recovered fissionable uranium from spent nuclear fuel rods and disposed of waste fluids by release to the regional aquifer and lithosphere. Environmental impacts were assessed by a monitoring well network. The conceptual model identifies multiple, highly variable, interacting, and transient components, including INEL facilities multiple operations and liquid waste handling, systems; the anisotropic, in homogeneous aquifer; the network of monitoring and production wells, and the intermittent flow of the Big Lost River. Pre anthropogenic natural conditions and early records of anthropogenic activities were sparsely or unreliably documented making reconstruction of natural conditions or early hydrologic impacts impossible or very broad characterizations

  4. Forecasting of Groundwater Level using Artificial Neural Network by incorporating river recharge and river bank infiltration

    Directory of Open Access Journals (Sweden)

    Nizar Shamsuddin Mohd Khairul

    2017-01-01

    Full Text Available Groundwater tables forecasting during implemented river bank infiltration (RBI method is important to identify adequate storage of groundwater aquifer for water supply purposes. This study illustrates the development and application of artificial neural networks (ANNs to predict groundwater tables in two vertical wells located in confined aquifer adjacent to the Langat River. ANN model was used in this study is based on the long period forecasting of daily groundwater tables. ANN models were carried out to predict groundwater tables for 1 day ahead at two different geological materials. The input to the ANN models consider of daily rainfall, river stage, water level, stream flow rate, temperature and groundwater level. Two different type of ANNs structure were used to predict the fluctuation of groundwater tables and compared the best forecasting values. The performance of different models structure of the ANN is used to identify the fluctuation of the groundwater table and provide acceptable predictions. Dynamics prediction and time series of the system can be implemented in two possible ways of modelling. The coefficient correlation (R, Mean Square Error (MSE, Root Mean Square Error (RMSE and coefficient determination (R2 were chosen as the selection criteria of the best model. The statistical values for DW1 are 0.8649, 0.0356, 0.01, and 0.748 respectively. While for DW2 the statistical values are 0.7392, 0.0781, 0.0139, and 0.546 respectively. Based on these results, it clearly shows that accurate predictions can be achieved with time series 1-day ahead of forecasting groundwater table and the interaction between river and aquifer can be examine. The findings of the study can be used to assist policy marker to manage groundwater resources by using RBI method.

  5. Holocene river history of the Danube: human-environment interactions on its islands in Hungary

    Science.gov (United States)

    Viczián, István; Balogh, János; Kis, Éva; Szeberényi, József

    2016-04-01

    A change in the frequency and magnitude of floods is the main response of river systems to climatic change. Natural floods are highly sensitive to even modest changes of climate. The discharge and the characteristics of floods basically determine the floodplain evolution and the feasibility of human land use and inhabitation on the islands and floodplains. The study revealed that those small islands of large rivers which have the surface rising only some meters above the river are particularly suitable research objects of Holocene climate variability as they are exposed to floods, react sensitively to environmental changes and their evolution may be paralleled with human history. The research area covers the islands of the Danube along the river between Komárom and Paks in Hungary, which is about 250 km, includes more than 50 smaller or formerly existing islands and two extensive islands: the Szentendre Island and Csepel Island. Data gathered from 570 archaeological sites of those islands from Neolithic to Modern Ages were analysed and interpreted in accordance with climate history and floodplain evolution. Nevertheless, the study is not only about river and its environmental history but it demonstrates the role of river and climatic variability in the history of mankind. The environment of the floodplain, the river hydrology, the sedimentation, the formation of islands and the incision and aggradation of surrounding riverbeds, the frequency of devastating floods have significantly changed through the historical time periods, which is reflected in the number and locations of archaeological sites on the islands. Their occupation history reflects the changes in discharge, climate, geomorphology, floods and human impacts and indicates historical periods with low or high probability of inundation. The most favourable periods for an island's occupation concerning the flood risk of its surfaces - and consequently of the banks along the river - are the first parts of a

  6. A proposal of conceptual model for Pertuso Spring discharge evaluation in the Upper Valley of Aniene River

    Directory of Open Access Journals (Sweden)

    Giuseppe Sappa

    2016-10-01

    Full Text Available The Upper Aniene River basin is part of a large karst aquifer, which interacts with the river, and represents the most important water resource in the southeast part of Latium Region, Central Italy, used for drinking, agriculture and hydroelectric supplies. This work provides hydrogeochemical data and their interpretations for 1 spring and 2 cross section of Aniene River, monitored from July 2014 to December 2015, in the Upper Valley of Aniene River, to identify flow paths and hydrogeochemical processes governing groundwater-surface water interactions in this region. These activities deal with the Environmental Monitoring Plan made for the catchment work project of the Pertuso Spring, in the Upper Valley of Aniene River, which is going to be exploited to supply an important drinking water network in the South part of Rome district. Discharge measurements and hydrogeochemical data were analyzed to develop a conceptual model of aquifer-river interaction, with the aim of achieving proper management and protection of this important hydrogeological system. All groundwater samples are characterized as Ca-HCO3 type. Geochemical modeling and saturation index computation of the water samples show that groundwater and surface water chemistry in the study area was evolved through the interaction with carbonate minerals. All groundwater samples were undersaturated with respect to calcite and dolomite, however some of the Aniene River samples were saturated with respect to dolomite. The analysis of Mg2+/Ca2+ ratios indicates that the dissolution of carbonate minerals is important for groundwater and surface water chemistry, depending on the hydrological processes, which control the groundwater residence time and chemical equilibria in the aquifer.

  7. Understanding the controls on sediment-P interactions and dynamics along a non-tidal river system in a rural–urban catchment: The River Nene

    International Nuclear Information System (INIS)

    Tye, A.M.; Rawlins, B.G.; Rushton, J.C.; Price, R.

    2016-01-01

    The release of Phosphorus (P) from river sediments has been identified as a contributing factor to waters failing the criteria for ‘Good Ecological Status’ under the EU Water Framework Directive (WFD). To identify the contribution of sediment-P to river systems, an understanding of the factors that influence its distribution within the entire non-tidal system is required. Thus the aims of this work were to examine the (i) total (P_T_o_t_a_l) and labile (P_L_a_b_i_l_e) concentrations in sediment, (ii) the sequestration processes and (iii) the interactions between sediment P and the river water in the six non-tidal water bodies of the River Nene, U.K. Collection of sediments followed a long period of flooding and high stream flow. In each water body, five cores were extracted and homogenised for analysis with an additional core being taken and sampled by depth increments. Comparing the distribution of sediment particle size and P_T_o_t_a_l data with soil catchment geochemical survey data, large increases in P_T_o_t_a_l were identified in sediments from water body 4–6, where median concentrations of P_T_o_t_a_l in the sediment (3603 mg kg"−"1) were up to double those of the catchment soils. A large proportion of this increase may be related to in-stream sorption of P, particularly from sewage treatment facilities where the catchment becomes more urbanised after water body 3. A linear correlation (r = 0.8) between soluble reactive phosphate (SRP) and Boron in the sampled river waters was found suggesting increased STW input in water bodies 4–6. P_L_a_b_i_l_e concentrations in homogenised cores were up to 100 mg kg"−"1 PO_4–P (generally < 2% of P_T_o_t_a_l) and showed a general increase with distance from the headwaters. A general increase in Equilibrium Phosphate Concentrations (EPC_0) from an average of 0.9–∼1.7 μm L"−"1 was found between water bodies 1–3 and 4–6. Fixation within oxalate extractable phases (Al, Fe and Mn) accounted

  8. Chemical and carbon isotope composition of Varzeas sediments and its interactions with some Amazon basin rivers

    International Nuclear Information System (INIS)

    Martinelli, L.A.

    1986-01-01

    Varzea sediment samples were collected on the banks of Amazon rivers and in the most important tributaires. The samples were taken in three different river stages. The major cations, pH, total nitrogen, total phosphorus, carbon and δ 13 C values were determined. The concentration of major basic cations - Ca,Mg,K e Na were greater in the main channel sediments than in the tributaires. Probably the differences in the substrats geology and erosion regimes of the basins account for this patterns, generally. The major basic cation, total phosphorus and carbon concentration were lower in the low Amazon Varzeas. Between the three differents sampling periods, pratically the elements concentration in Varzea sediment was constant. Finally, the datas showed that the most parts of Varzea carbon sediment had it's origin in the fine particulated organic matter transported by the Amazon river. (C.D.G.) [pt

  9. EPA Sole Source Aquifers

    Data.gov (United States)

    U.S. Environmental Protection Agency — Information on sole source aquifers (SSAs) is widely used in assessments under the National Environmental Policy Act and at the state and local level. A national...

  10. Tracers Detect Aquifer Contamination

    National Research Council Canada - National Science Library

    Enfield, Carl

    1995-01-01

    The EPA's National Laboratory (NRMRL) at Ada, OK, along with the University of Florida and the University of Texas, have developed a tracer procedure to detect the amount of contamination in aquifer formations...

  11. Tracking groundwater discharge to a large river using tracers and geophysics.

    Science.gov (United States)

    Harrington, Glenn A; Gardner, W Payton; Munday, Tim J

    2014-01-01

    Few studies have investigated large reaches of rivers in which multiple sources of groundwater are responsible for maintaining baseflow. This paper builds upon previous work undertaken along the Fitzroy River, one of the largest perennial river systems in north-western Australia. Synoptic regional-scale sampling of both river water and groundwater for a suite of environmental tracers ((4) He, (87) Sr/(86) Sr, (222) Rn and major ions), and subsequent modeling of tracer behavior in the river, has enabled definition and quantification of groundwater input from at least three different sources. We show unambiguous evidence of both shallow "local" groundwater, possibly recharged to alluvial aquifers beneath the adjacent floodplain during recent high-flow events, and old "regional" groundwater introduced via artesian flow from deep confined aquifers. We also invoke hyporheic exchange and either bank return flow or parafluvial flow to account for background (222) Rn activities and anomalous chloride trends along river reaches where there is no evidence of the local or regional groundwater inputs. Vertical conductivity sections acquired through an airborne electromagnetic (AEM) survey provide insights to the architecture of the aquifers associated with these sources and general groundwater quality characteristics. These data indicate fresh groundwater from about 300 m below ground preferentially discharging to the river, at locations consistent with those inferred from tracer data. The results demonstrate how sampling rivers for multiple environmental tracers of different types-including stable and radioactive isotopes, dissolved gases and major ions-can significantly improve conceptualization of groundwater-surface water interaction processes, particularly when coupled with geophysical techniques in complex hydrogeological settings. © 2013, National Ground Water Association.

  12. Ogallala Aquifer Mapping Program

    International Nuclear Information System (INIS)

    1984-10-01

    A computerized data file has been established which can be used efficiently by the contour-plotting program SURFACE II to produce maps of the Ogallala aquifer in 17 counties of the Texas Panhandle. The data collected have been evaluated and compiled into three sets, from which SURFACE II can generate maps of well control, aquifer thickness, saturated thickness, water level, and the difference between virgin (pre-1942) and recent (1979 to 1981) water levels. 29 figures, 1 table

  13. Characterisation of the Ionian-Lucanian coastal plain aquifer

    OpenAIRE

    Polemio, M.; Limoni, P.P.; Mitolo, D.; Santaloia, F.

    2002-01-01

    This paper deals with a Southern Italy area, 40 km by 10 km wide, located where four river valleys anastomose themselves in the coastal plain. The geological and hydrogeological features of the study area and the chemical-physical groundwater characterisation have been inferred from the data analysis of 1130 boreholes. Some aquifers, connected among them, constituted by soils of different geological origin -marine terraces deposits, river valley alluvial deposits and alluvial and coastal depo...

  14. Hydrochemistry of New Zealand's aquifers

    International Nuclear Information System (INIS)

    Rosen, M.R.

    2001-01-01

    Groundwater chemistry on a national scale has never been studied in New Zealand apart from a few studies on nitrate concentrations and pesticides. These studies are covered in Chapter 8 of this book. However general studies of groundwater chemistry, groundwater-rock interaction and regional characteristics of water quality have not been previously addressed in much detail. This is partly because New Zealand aquifers are relatively small on a world scale and are geologically and tectonically diverse (see Chapter 3). But New Zealand has also recently lacked a centralised agency responsible for groundwater quality, and therefore, no national assessments have been undertaken. In recent years, the Institute of Geological and Nuclear Sciences has managed a programme of collecting and analysing the groundwater chemistry of key New Zealand aquifers. This programme is called the National Groundwater Monitoring Programme (NGMP) and is funded by the New Zealand Public Good Science Fund. The programme started in 1990 using only 22 wells, with four regional authorities of the country participating. The NGMP now includes all 15 regional and unitary authorities that use groundwater and over 100 monitoring sites. The NGMP is considered a nationally significant database by the New Zealand Foundation for Research Science and Technology. The NGMP allows a national comparison of aquifer chemistries because the samples are all analysed at one laboratory in a consistent manner and undergo stringent quality control checks. Poor quality analyses are thus minimised. In addition, samples are collected quarterly so that long-term seasonal trends in water quality can be analysed, and the effects of changes in land use and the vulnerability of aquifers to contaminant leaching can be assessed. This chapter summarises the water quality data collected for the NGMP over the past 10 years. Some records are much shorter than others, but most are greater than three years. Additional information is

  15. Characterization of meter-scale spatial variability of riverbed hydraulic conductivity in a lowland river (Aa River, Belgium)

    Science.gov (United States)

    Ghysels, Gert; Benoit, Sien; Awol, Henock; Jensen, Evan Patrick; Debele Tolche, Abebe; Anibas, Christian; Huysmans, Marijke

    2018-04-01

    An improved general understanding of riverbed heterogeneity is of importance for all groundwater modeling studies that include river-aquifer interaction processes. Riverbed hydraulic conductivity (K) is one of the main factors controlling river-aquifer exchange fluxes. However, the meter-scale spatial variability of riverbed K has not been adequately mapped as of yet. This study aims to fill this void by combining an extensive field measurement campaign focusing on both horizontal and vertical riverbed K with a detailed geostatistical analysis of the meter-scale spatial variability of riverbed K . In total, 220 slug tests and 45 standpipe tests were performed at two test sites along the Belgian Aa River. Omnidirectional and directional variograms (along and across the river) were calculated. Both horizontal and vertical riverbed K vary over several orders of magnitude and show significant meter-scale spatial variation. Horizontal K shows a bimodal distribution. Elongated zones of high horizontal K along the river course are observed at both sections, indicating a link between riverbed structures, depositional environment and flow regime. Vertical K is lognormally distributed and its spatial variability is mainly governed by the presence and thickness of a low permeable organic layer at the top of the riverbed. The absence of this layer in the center of the river leads to high vertical K and is related to scouring of the riverbed by high discharge events. Variograms of both horizontal and vertical K show a clear directional anisotropy with ranges along the river being twice as large as those across the river.

  16. The patterns of organisation and structure of interactions in a fish-parasite network of a neotropical river.

    Science.gov (United States)

    Bellay, Sybelle; Oliveira, Edson F de; Almeida-Neto, Mário; Abdallah, Vanessa D; Azevedo, Rodney K de; Takemoto, Ricardo M; Luque, José L

    2015-07-01

    The use of the complex network approach to study host-parasite interactions has helped to improve the understanding of the structure and dynamics of ecological communities. In this study, this network approach is applied to evaluate the patterns of organisation and structure of interactions in a fish-parasite network of a neotropical Atlantic Forest river. The network includes 20 fish species and 73 metazoan parasite species collected from the Guandu River, Rio de Janeiro State, Brazil. According to the usual measures in studies of networks, the organisation of the network was evaluated using measures of host susceptibility, parasite dependence, interaction asymmetry, species strength and complementary specialisation of each species as well as the network. The network structure was evaluated using connectance, nestedness and modularity measures. Host susceptibility typically presented low values, whereas parasite dependence was high. The asymmetry and species strength were correlated with host taxonomy but not with parasite taxonomy. Differences among parasite taxonomic groups in the complementary specialisation of each species on hosts were also observed. However, the complementary specialisation and species strength values were not correlated. The network had a high complementary specialisation, low connectance and nestedness, and high modularity, thus indicating variability in the roles of species in the network organisation and the expected presence of many specialist species. Copyright © 2015 Australian Society for Parasitology Inc. Published by Elsevier Ltd. All rights reserved.

  17. Analytical solution of groundwater waves in unconfined aquifers with ...

    Indian Academy of Sciences (India)

    Selva Balaji Munusamy

    2017-07-29

    Jul 29, 2017 ... higher-order Boussinesq equation. The homotopy perturbation solution is derived using a virtual perturbation .... reality, seepage face formation is common for tide–aquifer interaction problems. To simplify the complexity of the.

  18. Agency interaction at the Savannah River Plant under the Endangered Species Act

    International Nuclear Information System (INIS)

    Mackey, H.E. Jr.

    1985-01-01

    The 300 square mile Savannah River Plant (SRP) offers a variety of protected habitats for endangered species including the alligator (resident), red-cockaded woodpecker (resident), short-nose sturgeon (migratory), and wood stork (fish-forager). The most recent of these four species to be listed by the US Fish and Wildlife Service (US FWS) is the wood stork. It had been observed prior to 1983 as an infrequent forager in the SRP Savannah River Swamp which adjoins SRP on the south and southwest. In anticipation of its listing as an endangered species, DOE-SR requested in the spring of 1983 that the Savannah River Ecology Laboratory, University of Georgia, conduct field surveys and studies of the nearest colony of wood storks to SRP (the Birdsville colony in north-central Georgia). The objective of these studies was to determine potential effects of the flooding of the Steel Creek swamp area with cooling water from L-Reactor. L-Reactor, which is proposed for restart, has not been operated since 1968. The survey found that wood storks forage in the Steel Creek delta swamp area of the Savannah River at SRP. Based on the numbers of storks at various foraging locations, sites at SRP ranked higher than non-SRP sites during the pre-fledging phase of the colony. Cold flow testing of L-Reactor also demonstrated that foraging sites in the Steel Creek delta would be unavailable during L-Reactor operation because of increased water levels

  19. Quantification of sediment-water interactions in a polluted tropical river through biogeochemical modeling

    NARCIS (Netherlands)

    Trinh, A.D.; Meysman, F.; Rochelle-Newall, E.; Bonnet, M.P.

    2012-01-01

    Diagenetic modeling presents an interesting and robust way to understand sediment-water column processes. Here we present the application of such a model to the Day River in Northern Vietnam, a system that is subject to high levels of domestic wastewater inputs from the Hanoi metropolitan area.

  20. Interactions between land use and flood management in the Chi River Basin

    NARCIS (Netherlands)

    Kuntiyawichai, K.

    2012-01-01

    The damages and hardships caused by floods and flooding remain an issue and are continuously increasing in the Chi River Basin, Thailand. It is difficult to make an accurate assessment of the costs and consequences associated with floods. However, flood hazards can also be seen as an opportunity, a

  1. Focus on CSIR research in water resource: Aquifer dependent ecosystems.

    CSIR Research Space (South Africa)

    Colvin, C

    2007-08-01

    Full Text Available of rivers. In terrestrial and riparian ecosystems, groundwater is not seen at the surface but is tapped by plants and used as ‘cryptic’ discharge. ADEs are important indicators of aquifer health and flow regimes. An oasis is a classic ADE, and like many...

  2. Hydrogeological and hydrochemical characterization of unconfined aquifer located in the alteration mantle of the Serra Geral Formation, in the Taquari-Antas river basin, northeast of Rio Grande do Sul State

    Directory of Open Access Journals (Sweden)

    Gisele Cemin

    2012-08-01

    Full Text Available This paper presents the hydrogeological and hydrochemical characterization of the unconfined aquifer located in the alteration mantle in the volcanic rocks from Serra Geral Formation, in the northeast region of Rio Grande do Sul State. This aquifer is conditioned by the soil, topography, lithology and climate, being characterized by a saturated layer thinner than 1,7 m, static levels between 0 and 1 m and low flow (<0,5 m3/h. These waters are of calcium or magnesium bicarbonate type, and low alkalinity and electrical conductivity, low calcium, magnesium, sodium, potassium and chloride concentrations, and high iron and manganese concentrations. Additionally, these waters have high concentration of nitrates (mean above 10 mg/L and the presence of total coliforms. These characteristics evidence a quick circulation between the recharging and discharge zones in the aquifer.

  3. Identification of the microbes mediating Fe reduction in a deep saline aquifer and their influence during managed aquifer recharge.

    Science.gov (United States)

    Ko, Myoung-Soo; Cho, Kyungjin; Jeong, Dawoon; Lee, Seunghak

    2016-03-01

    In this study, indigenous microbes enabling Fe reduction under saline groundwater conditions were identified, and their potential contribution to Fe release from aquifer sediments during managed aquifer recharge (MAR) was evaluated. Sediment and groundwater samples were collected from a MAR feasibility test site in Korea, where adjacent river water will be injected into the confined aquifer. The residual groundwater had a high salinity over 26.0 psu, as well as strong reducing conditions (dissolved oxygen, DOaquifer were found to be Citrobacter sp. However, column experiments to simulate field operation scenarios indicated that additional Fe release would be limited during MAR, as the dominant microbial community in the sediment would shift from Citrobacter sp. to Pseudomonas sp. and Limnohabitans sp. as river water injection alters the pore water chemistry. Copyright © 2015 Elsevier B.V. All rights reserved.

  4. Preliminary subsurface hydrologic considerations: Columbia River Plateau Physiographic Province. Assessment of effectiveness of geologic isolation systems

    International Nuclear Information System (INIS)

    Veatch, M.D.

    1980-04-01

    This report contains a discussion of the hydrologic conditions of the Columbia River Plateau physiographic province. The Columbia River Plateau is underlain by a thick basalt sequence. The Columbia River basalt sequence contains both basalt flows and sedimentary interbeds. These sedimentary interbeds, which are layers of sedimentary rock between lava flows, are the main aquifer zones in the basalt sequence. Permeable interflow zones, involving the permeable top and/or rubble bottom of a flow, are also water-transmitting zones. A number of stratigraphic units are present in the Pasco Basin, which is in the central part of the Columbia River Plateau. At a conceptual level, the stratigraphic sequence from the surface downward can be separated into four hydrostratigraphic systems. These are: (1) the unsaturated zone, (2) the unconfined aquifer, (3) the uppermost confined aquifers, and (4) the lower Yakima basalt hydrologic sequence. A conceptual layered earth model (LEM) has been developed. The LEM represents the major types of porous media (LEM units) that may be encountered at a number of places on the Columbia Plateau, and specifically in the Pasco Basin. The conceptual LEM is not representative of the actual three-dimensional hydrostratigraphic sequence and hydrologic conditions existing at any specific site within the Columbia Plateau physiographic province. However, the LEM may be useful for gaining a better understanding of how the hydrologic regime may change as a result of disruptive events that may interact with a waste repository in geologic media

  5. An epidemic model for the interactions between thermal regime of rivers and transmission of Proliferative Kidney Disease in salmonid fish

    Science.gov (United States)

    Carraro, Luca; Bertuzzo, Enrico; Mari, Lorenzo; Gatto, Marino; Strepparava, Nicole; Hartikainen, Hanna; Rinaldo, Andrea

    2015-04-01

    Proliferative kidney disease (PKD) affects salmonid populations in European and North-American rivers. It is caused by the endoparasitic myxozoan Tetracapsuloides bryosalmonae, which exploits freshwater bryozoans (Fredericella sultana) and salmonids as primary and secondary hosts, respectively. Incidence and mortality, which can reach up to 90-100%, are known to be strongly related to water temperature. PKD has been present in brown trout population for a long time but has recently increased rapidly in incidence and severity causing a decline in fish catches in many countries. In addition, environmental changes are feared to cause PKD outbreaks at higher latitude and altitude regions as warmer temperatures promote disease development. This calls for a better comprehension of the interactions between disease dynamics and the thermal regime of rivers, in order to possibly devise strategies for disease management. In this perspective, a spatially explicit model of PKD epidemiology in riverine host metacommunities is proposed. The model aims at summarizing the knowledge on the modes of transmission of the disease and the life-cycle of the parasite, making the connection between temperature and epidemiological parameters explicit. The model accounts for both local population and disease dynamics of bryozoans and fish and hydrodynamic dispersion of the parasite spores and hosts along the river network. The model is time-hybrid, coupling inter-seasonal and intra-seasonal dynamics, the former being described in a continuous time domain, the latter seen as time steps of a discrete time domain. In order to test the model, a case study is conducted in river Wigger (Cantons of Aargau and Lucerne, Switzerland), where data about water temperature, brown trout and bryozoan populations and PKD prevalence are being collected.

  6. Assessment of the hydraulic connection between ground water and the Peace River, west-central Florida

    Science.gov (United States)

    Lewelling, B.R.; Tihansky, A.B.; Kindinger, J.L.

    1998-01-01

    . Generally, the upper Peace River is characterized by a shallow, buried irregular top of rock, numerous observed sinkholes, and subsidence depressions. The downward head gradient provides potential for the Peace River to lose water to the ground-water system. Along the middle Peace River area, head gradients alternate between downward and upward, creating both recharging and discharging ground-water conditions. Seismic records show that buried, laterally continuous reflectors in the lower Peace River pinch out in the middle Peace River streambed. Small springs have been observed along the streambed where these units pinch out. This area corresponds to the region where highest ground-water seepage volumes were measured during this study. Further south, along the lower Peace River, upward head gradients provide conditions for ground-water discharge into the Peace River. Generally, confinement between the surficial aquifer and the confined ground-water systems in this area is better than to the north. However, localized avenues for surface-water and ground-water interactions may exist along discontinuities observed in seismic reflectors associated with large-scale flexures or subsidence features. Ground-water seepage gains or losses along the Peace River were quantified by making three seepage runs during periods of: (1) low base flow, (2) high base flow, and (3) high flow. Low and high base-flow seepage runs were performed along a 74-mile length of the Peace River, between Bartow and Nocatee. Maximum losses of 17.3 cubic feet per second (11.2 million gallons per day) were measured along a 3.2-mile reach of the upper Peace River. The high-flow seepage run was conducted to quantify losses in the Peace River channel and floodplain between Bartow and Fort Meade. Seepage losses calculated during high-flow along a 7.2-mile reach of the Peace River, from the Clear Springs Mine bridge to the Mobil Mine bridge, were approximately 10 percent of the river flow, or 118 c

  7. Fragmentation and thermal risks from climate change interact to affect persistence of native trout in the Colorado River basin.

    Science.gov (United States)

    Roberts, James J; Fausch, Kurt D; Peterson, Douglas P; Hooten, Mevin B

    2013-05-01

    Impending changes in climate will interact with other stressors to threaten aquatic ecosystems and their biota. Native Colorado River cutthroat trout (CRCT; Oncorhynchus clarkii pleuriticus) are now relegated to 309 isolated high-elevation (>1700 m) headwater stream fragments in the Upper Colorado River Basin, owing to past nonnative trout invasions and habitat loss. Predicted changes in climate (i.e., temperature and precipitation) and resulting changes in stochastic physical disturbances (i.e., wildfire, debris flow, and channel drying and freezing) could further threaten the remaining CRCT populations. We developed an empirical model to predict stream temperatures at the fragment scale from downscaled climate projections along with geomorphic and landscape variables. We coupled these spatially explicit predictions of stream temperature with a Bayesian Network (BN) model that integrates stochastic risks from fragmentation to project persistence of CRCT populations across the upper Colorado River basin to 2040 and 2080. Overall, none of the populations are at risk from acute mortality resulting from high temperatures during the warmest summer period. In contrast, only 37% of populations have a ≥90% chance of persistence for 70 years (similar to the typical benchmark for conservation), primarily owing to fragmentation. Populations in short stream fragments <7 km long, and those at the lowest elevations, are at the highest risk of extirpation. Therefore, interactions of stochastic disturbances with fragmentation are projected to be greater threats than warming for CRCT populations. The reason for this paradox is that past nonnative trout invasions and habitat loss have restricted most CRCT populations to high-elevation stream fragments that are buffered from the potential consequences of warming, but at risk of extirpation from stochastic events. The greatest conservation need is for management to increase fragment lengths to forestall these risks. © 2013

  8. Environmental changes and human work in the region of the Upper Paraná River floodplain: processes and interactions

    Directory of Open Access Journals (Sweden)

    EA. Tomanik

    Full Text Available The environment and society constitute a complex of elements and interactions. Thus, an understanding of the processes in which the environment and psychosocial elements are involved may not be gained from knowledge of just one isolated variable. Based on such premises, the present paper, which summarizes the results of a series of studies, adopts work relationships as its main focus, but in addition, it has two complementary objectives. One is to present some analyses on the interaction between human actions and the environmental changes that have been taking place in the region of the Upper Paraná River floodplain and in its boundaries. A secondary aim is to show how those two factors have been changing people's working and living conditions and the identity configuration of some of the human groups that live at that site.

  9. Accounting for intracell flow in models with emphasis on water table recharge and stream-aquifer interaction: 1. Problems and concepts

    Science.gov (United States)

    Jorgensen, Donald G.; Signor, Donald C.; Imes, Jeffrey L.

    1989-01-01

    Intracell flow is important in modeling cells that contain both sources and sinks. Special attention is needed if recharge through the water table is a source. One method of modeling multiple sources and sinks is to determine the net recharge per cell. For example, for a model cell containing both a sink and recharge through the water table, the amount of recharge should be reduced by the ratio of the area of influence of the sink within the cell to the area of the cell. The reduction is the intercepted portion of the recharge. In a multilayer model this amount is further reduced by a proportion factor, which is a function of the depth of the flow lines from the water table boundary to the internal sink. A gaining section of a stream is a typical sink. The aquifer contribution to a gaining stream can be conceptualized as having two parts; the first part is the intercepted lateral flow from the water table and the second is the flow across the streambed due to differences in head between the water level in the stream and the aquifer below. The amount intercepted is a function of the geometry of the cell, but the amount due to difference in head across the stream bed is largely independent of cell geometry. A discharging well can intercept recharge through the water table within a model cell. The net recharge to the cell would be reduced in proportion to the area of influence of the well within the cell. The area of influence generally changes with time. Thus the amount of intercepted recharge and net recharge may not be constant with time. During periods when the well is not discharging there will be no intercepted recharge even though the area of influence from previous pumping may still exist. The reduction of net recharge per cell due to internal interception of flow will result in a model-calculated mass balance less than the prototype. Additionally the “effective transmissivity” along the intercell flow paths may be altered when flow paths are occupied by

  10. Bedrock aquifers of eastern San Juan County, Utah

    Science.gov (United States)

    Avery, Charles

    1986-01-01

    This study is one of a series of studies appraising the waterbearing properties of the Navajo Sandstone and associated formations in southern Utah.  The study area is about 4,600 square miles, extending from the Utah-Arizona State line northward to the San Juan-Grand County line and westward from the Utah-Colorado State line to the longitude of about 109°50'.Some of the water-yielding formations are grouped into aquifer systems. The C aquifer is comprised of the DeChelly Sandstone Member of the Cutler Formation.  The P aquifer is comprised of the Cedar Mesa Member of the Cutler Formation and the undifferentiated Cutler Formation. The N aquifer is comprised of the sedimentary section that includes the Wingate Sandstone, Kayenta Formation, Navajo Sandstone, Carmel Formation, and Entrada sandstone.  The M aquifer is comprised of the Bluff Sandstone Member and other sandstone units of the Morrison Formation.  The D aquifer is comprised of the Burro Canyon Formation and Dakota Sandstone.  Discharge from the ground-water reservoir to the San Juan River between gaging stations at Four Corners and Mexican Hat is about 66 cubic feet per second.The N aquifer is the main aquifer in the study area. Recharge by infiltration of precipitation is estimated to be 25,000 acre-feet per year.  A major ground-water divide exists under the broad area east of Monticello.  The thickness of the N aquifer, where the sedimentary section is fully preserved and saturated, generally is 750 to 1,250 feet.   Hydraulic conductivity values obtained from aquifer tests range from 0.02 to 0.34 foot per day.  The total volume of water in transient storage is about 11 million acre-feet. Well discharge somewhat exceeded 2,340 acre-feet during 1981.  Discharge to the San Juan River from the N aquifer is estimated to be 6.9 cubic feet per second. Water quality ranges from a calcium bicarbonate to sodium chloride type water

  11. The Suwannee River Hydrologic Observatory: A Subtropical Coastal Plain Watershed in Transition

    Science.gov (United States)

    Graham, W. D.

    2004-12-01

    . In addition, population growth is fueling increased groundwater withdrawals from the Floridan aquifer for local consumption affecting water supply. Inter-basin transfers from the lower Suwannee River to south Florida have been suggested as one solution to south Florida's growing water crisis. Three Distinct Hydrologic Regimes - The Suwannee River watershed comprises three distinct but linked hydrologic landscape units. The upper Suwannee River interacts with the surficial aquifer but is largely separated from the Floridan aquifer by a confining unit. The middle Suwannee River interacts with both surficial aquifers and the unconfined karstic Floridan aquifer. The lower Suwannee River discharges to a deltaic estuary as surface water along with diffuse submarine groundwater discharge. Extensive Existing Data Infrastructure - Some discharge data exists from the turn of the 19th century to the present. More recently, the USDA Agricultural Research Service through the Southeast Watershed Research Laboratory (SEWRL) has monitored the Little River watershed in Georgia at the headwaters of the Suwannee River since 1965, and the Suwannee River Water Management District (SRWMD) has monitored the Suwannee River watershed in Florida since 1972. Other groups (USGS, Suwannee River Partnership, and individual university investigators) have long worked on specific, local geological, hydrological, and biological problems within the watershed. Contributing Organizations: University of Florida, Florida State University, University of South Florida, University of Central Florida, University of Georgia, USGS, USDA, and SRWMD

  12. Determining flow, recharge, and vadose zone drainage in an unconfined aquifer from groundwater strontium isotope measurements, Pasco Basin, WA

    International Nuclear Information System (INIS)

    2004-01-01

    Strontium isotope compositions (87Sr/86Sr) measured in groundwater samples from 273 wells in the Pasco Basin unconfined aquifer below the Hanford Site show large and systematic variations that provide constraints on groundwater recharge, weathering rates of the aquifer host rocks, communication between unconfined and deeper confined aquifers, and vadose zone-groundwater interaction. The impact of millions of cubic meters of wastewater discharged to the vadose zone (103-105 times higher than ambient drainage) shows up strikingly on maps of groundwater 87Sr/86Sr. Extensive access through the many groundwater monitoring wells at the site allows for an unprecedented opportunity to evaluate the strontium geochemistry of a major aquifer, hosted primarily in unconsolidated sediments, and relate it to both long term properties and recent disturbances. Groundwater 87Sr/86Sr increases systematically from 0.707 to 0.712 from west to east across the Hanford Site, in the general direction of groundwater flow, as a result of addition of Sr from the weathering of aquifer sediments and from diffuse drainage through the vadose zone. The lower 87Sr/86Sr groundwater reflects recharge waters that have acquired Sr from Columbia River Basalts. Based on a steady-state model of Sr reactive transport and drainage, there is an average natural drainage flux of 0-1.4 mm/yr near the western margin of the Hanford Site, and ambient drainage may be up to 30 mm/yr in the center of the site assuming an average bulk rock weathering rate of 10-7.5 g/g/yr

  13. Hydrogeology and water-quality characteristics of the Lower Floridan aquifer in east-central Florida

    Science.gov (United States)

    O'Reilly, Andrew M.; Spechler, Rick M.; McGurk, Brian E.

    2002-01-01

    surface of the Lower Floridan aquifer ranged from about 16 to 113 feet above sea level, and altitudes in May 1999 were about 2 to 7 feet lower than those measured in September 1998. The potentiometric surface of the Floridan aquifer system is constantly fluctuating, mainly in response to seasonal variations in rainfall and ground-water withdrawals. Seasonal fluctuations in the Lower Floridan aquifer typically range from about 2 to 10 feet. Water samples from 50 Lower Floridan aquifer wells were collected during this study. Most samples were analyzed in the field for temperature, pH, and specific conductance, and in the laboratory for major cations and anions. Specific conductance ranged from 147 to 6,710 microsiemens per centimeter. Chloride concentrations ranged from 3.0 to 2,188 milligrams per liter; sulfate concentrations ranged from 0.2 to 750 milli-grams per liter; and hardness ranged from 69 to 940 milligrams per liter. Water was least mineralized in the recharge areas of the Lower Floridan aquifer in the western part of the study area. The most mineralized water in the Lower Floridan aquifer occurred along parts of the Wekiva and St. Johns Rivers and in much of the eastern and southern parts of the study area. The altitude of the base of freshwater in the Floridan aquifer system (where chloride concentrations are equal to 250 milligrams per liter) is variable throughout the study area. The estimated position of the 250 milligram per liter isochlor surface is less than 200 feet below sea level in much of the eastern part of the study area, including the areas along the St. Johns River in Lake, Seminole, and Volusia Counties and near the Wekiva River in western Seminole County. The altitude of the 250 milligram per liter isochlor exceeds 3,000 feet below sea level in the extreme southwestern part of the study area.

  14. Occurrence of Pharmaceuticals in Wastewater and Their Interaction with Shallow Aquifers: A Case Study of Horní Beřkovice, Czech Republic

    Directory of Open Access Journals (Sweden)

    David Rozman

    2017-03-01

    Full Text Available The application of innovative technologies in water management, such as wastewater reuse, requires a deeper understanding of emerging pollutants, including pharmaceuticals. This study presents a unique pilot site at Horní Beřkovice in Central Bohemia, where wastewater parameters are significantly influenced by the effluent from a local psychiatric hospital, and where the treated wastewater infiltrates into a shallow aquifer over a long period. The survey compared the quality parameters of local wastewater with those of the wastewater in four other catchments with no sources of concentrated pharmaceutical contamination. A total of 10 pharmaceuticals were detected while monitoring a common sewage system, but their number increased 3-fold at Horní Beřkovice. The water quality data revealed the effectiveness of the removal of pharmaceuticals from wastewater at the local sewage treatment plant and tracked the fate of substances that move from the treatment plant into the recharge ponds and then gradually into groundwater. The findings showed a significant decrease in all the monitored micropollutants that remained bound in sediments and in the unsaturated zone. Their passage into groundwater was highly reduced, and they virtually disappear after a few hundred meters in the saturated zone. The only exception is carbamazepine. This substance passes through the treatment technology and unsaturated zone. It systematically appears in the groundwater samples collected about 1 km from the infiltration site.

  15. Residence times and mixing of water in river banks: implications for recharge and groundwater - surface water exchange

    Science.gov (United States)

    Unland, N. P.; Cartwright, I.; Cendón, D. I.; Chisari, R.

    2014-02-01

    The residence time of groundwater within 50 m of the Tambo River, South East Australia, has been estimated through the combined use of 3H and 14C. Groundwater residence times increase towards the Tambo River which implies a gaining river system and not increasing bank storage with proximity to the Tambo River. Major ion concentrations and δ2H and δ18O values of bank water also indicate that bank infiltration does not significantly impact groundwater chemistry under baseflow and post-flood conditions, suggesting that the gaining nature of the river may be driving the return of bank storage water back into the Tambo River within days of peak flood conditions. The covariance between 3H and 14C indicates the leakage and mixing between old (~17 200 yr) groundwater from a semi-confined aquifer and younger groundwater (bank storage, as rapid pressure propagation into the semi-confined aquifer during flooding will minimise bank infiltration. This study illustrates the complex nature of river groundwater interactions and the potential downfall in assuming simple or idealised conditions when conducting hydrogeological studies.

  16. SRP baseline hydrogeologic investigation: Aquifer characterization

    Energy Technology Data Exchange (ETDEWEB)

    Strom, R.N.; Kaback, D.S.

    1992-03-31

    An investigation of the mineralogy and chemistry of the principal hydrogeologic units and the geochemistry of the water in the principal aquifers at Savannah River Site (SRS) was undertaken as part of the Baseline Hydrogeologic Investigation. This investigation was conducted to provide background data for future site studies and reports and to provide a site-wide interpretation of the geology and geochemistry of the Coastal Plain Hydrostratigraphic province. Ground water samples were analyzed for major cations and anions, minor and trace elements, gross alpha and beta, tritium, stable isotopes of hydrogen, oxygen, and carbon, and carbon-14. Sediments from the well borings were analyzed for mineralogy and major and minor elements.

  17. Origin and residence time of water in the Lima aquifer

    Energy Technology Data Exchange (ETDEWEB)

    Montoya, Modesto [Instituto Peruano de Energia Nuclear, Av. Canada 1470, San Borja, Lima (Peru); Universidad Nacional de Ingenieria, Av. Tupac Amaru 210, Rimac, Lima (Peru); Mamani, Enoc [Direccion de Servicios, Instituto Peruano de Energia Nuclear, Av. Jose Saco km 12.5, Carabayllo, Lima (Peru)

    2013-07-01

    The 8 million inhabitants of the coastal city Lima are supplied with water from the Rimac and Chillon rivers and water wells in the Lima aquifer. The history of the Rimac River flow and static level of water in its wells have been correlated to calculate the residence time of water in the aquifer it is recharged by the Rimac River until it reaches a well located 12 km away in the Miraflores District near the sea. The relative abundance of {sup 2}H and {sup 18}O are used to identify the origins of the waters from those wells, and the {sup 3}H and {sup 14}C contents are used to estimate the time after they fall as rain. (authors).

  18. Origin and residence time of water in the Lima aquifer

    International Nuclear Information System (INIS)

    Montoya, Modesto; Mamani, Enoc

    2013-01-01

    The 8 million inhabitants of the coastal city Lima are supplied with water from the Rimac and Chillon rivers and water wells in the Lima aquifer. The history of the Rimac River flow and static level of water in its wells have been correlated to calculate the residence time of water in the aquifer it is recharged by the Rimac River until it reaches a well located 12 km away in the Miraflores District near the sea. The relative abundance of 2 H and 18 O are used to identify the origins of the waters from those wells, and the 3 H and 14 C contents are used to estimate the time after they fall as rain. (authors).

  19. Interactions between the flooding regime and floodplain grasslands in the Tana River Delta, in Kenya

    Science.gov (United States)

    Leauthaud, Crystele; Musila, Winfred; Duvail, Stéphanie; Kergoat, Laurent; Hiernaux, Pierre; Grippa, Manuela; Albergel, Jean

    2017-04-01

    The floodplain grasslands of the Tana River Delta, located on the East African coast in Kenya, form part of an intertwined socio-ecological deltaic system of high biodiversity value that delivers numerous goods and services. Mainly composed of Echinochloa stagnina (Retz) P. Beauv., a high-value forage species, this ecosystem is the major dry-season grazing grounds of the local pastoralist communities. The construction of hydroelectric infrastructure has led to a modification of the flooding regime. The impacts of the resulting reduction of floods in the deltaic zone on ecosystem properties and services still need to be assessed. In such a perspective, this study characterizes the link between the flooding regime of the Tana River and the growth pattern of its floodplain grassland. Aboveground dry phytomass was sampled for 15 months under a wide variety of naturally flooded and non-flooded conditions and controlled irrigation and cutting frequency treatments. Annual aboveground dry phytomass attained high values between 11 T.ha-1 and 32 T.ha-1 and annual net primary production of the grasslands reached 35 T.ha-1.year-1. Growth rates clearly depended on the flooding regime, management and climate conditions and were on average more than twice as fast during, and 50% faster after the floods, relative to pre-flood conditions. A plant growth model allowed testing the effect of different flooding regimes on plant productivity, confirming very low productivity in the absence of floods. These results suggest that rangeland and water management for the Tana River deltaic wetlands are tightly linked. The projected construction of another dam could lead to a reduction of flood extent and period and a decrease of grassland productivity and growth duration. Mitigation of this type of negative impacts, which will have direct and adverse consequences for the pastoralist communities as well as on the delivery of other goods and services, needs to be undertaken.

  20. Surface-water and groundwater interactions in an extensively mined watershed, upper Schuylkill River, Pennsylvania, USA

    Science.gov (United States)

    Cravotta,, Charles A.; Goode, Daniel J.; Bartles, Michael D.; Risser, Dennis W.; Galeone, Daniel G.

    2014-01-01

    Streams crossing underground coal mines may lose flow, while abandoned mine drainage (AMD) restores flow downstream. During 2005-12, discharge from the Pine Knot Mine Tunnel, the largest AMD source in the upper Schuylkill River Basin, had near-neutral pH and elevated concentrations of iron, manganese, and sulfate. Discharge from the tunnel responded rapidly to recharge but exhibited a prolonged recession compared to nearby streams, consistent with rapid infiltration and slow release of groundwater from the mine. Downstream of the AMD, dissolved iron was attenuated by oxidation and precipitation while dissolved CO2 degassed and pH increased. During high-flow conditions, the AMD and downstream waters exhibited decreased pH, iron, and sulfate with increased acidity that were modeled by mixing net-alkaline AMD with recharge or runoff having low ionic strength and low pH. Attenuation of dissolved iron within the river was least effective during high-flow conditions because of decreased transport time coupled with inhibitory effects of low pH on oxidation kinetics. A numerical model of groundwater flow was calibrated using groundwater levels in the Pine Knot Mine and discharge data for the Pine Knot Mine Tunnel and the West Branch Schuylkill River during a snowmelt event in January 2012. Although the calibrated model indicated substantial recharge to the mine complex took place away from streams, simulation of rapid changes in mine pool level and tunnel discharge during a high flow event in May 2012 required a source of direct recharge to the Pine Knot Mine. Such recharge produced small changes in mine pool level and rapid changes in tunnel flow rate because of extensive unsaturated storage capacity and high transmissivity within the mine complex. Thus, elimination of stream leakage could have a small effect on the annual discharge from the tunnel, but a large effect on peak discharge and associated water quality in streams.

  1. Exploring the Tuolumne River:An Interactive CD ROM on Fluvial Processes

    Science.gov (United States)

    Reid, J. B.; Murray, D. D.; Sammons, J. I.; Woolf, B.; Kidder, J.

    2001-12-01

    We have created an electronic field investigation to help students discover the dynamics of river processes using the example of the Tuolumne River, in Yosemite National Park. The experience simulates a field trip to Tuolumne Meadows, where the students make a series of visual observations based on ground and aerial photographs. We want them to build as full a set of objective observations as possible before they engage in interpretation. The program records the specific locations in the photographs where the observations have been made, allowing an electronic assessment of the diversity of the students' descriptions. Students also "acquire" real field data (bathymetry, flow and grain size distributions, and the outer bank position through time) in a two stage process: (1) they predict the bathymetry, the flow patterns, etc. based on a careful scrutiny of the photographs and (2) they "do the experiments" to get the real field data. The computer then evaluates the match in each case, and asks a series of tailored socratic questions to lead the students to a richer understanding. When the "observations" are complete, we help them organize a logically sequential Results Section, and then a self-consistent hypothesis. Finally, for further investigation, we provide a set of photographs of other ivers, each of which has a rich "story" of its own. Our goals for this project are: (1) to have students discover for themselves how rivers "work" at their own pace and level of sophistication, and (2) to model the scientific method so that it can applied to other geologic investigations.

  2. Interacting effects of discharge and channel morphology on transport of semibuoyant fish eggs in large, altered river systems.

    Directory of Open Access Journals (Sweden)

    Thomas A Worthington

    Full Text Available Habitat fragmentation and flow regulation are significant factors related to the decline and extinction of freshwater biota. Pelagic-broadcast spawning cyprinids require moving water and some length of unfragmented stream to complete their life cycle. However, it is unknown how discharge and habitat features interact at multiple spatial scales to alter the transport of semi-buoyant fish eggs. Our objective was to assess the relationship between downstream drift of semi-buoyant egg surrogates (gellan beads and discharge and habitat complexity. We quantified transport time of a known quantity of beads using 2-3 sampling devices at each of seven locations on the North Canadian and Canadian rivers. Transport time was assessed based on median capture time (time at which 50% of beads were captured and sampling period (time period when 2.5% and 97.5% of beads were captured. Habitat complexity was assessed by calculating width∶depth ratios at each site, and several habitat metrics determined using analyses of aerial photographs. Median time of egg capture was negatively correlated to site discharge. The temporal extent of the sampling period at each site was negatively correlated to both site discharge and habitat-patch dispersion. Our results highlight the role of discharge in driving transport times, but also indicate that higher dispersion of habitat patches relates to increased retention of beads within the river. These results could be used to target restoration activities or prioritize water use to create and maintain habitat complexity within large, fragmented river systems.

  3. Effects of dams on downstream molluscan predator-prey interactions in the Colorado River estuary.

    Science.gov (United States)

    Smith, Jansen A; Handley, John C; Dietl, Gregory P

    2018-05-30

    River systems worldwide have been modified for human use and the downstream ecological consequences are often poorly understood. In the Colorado River estuary, where upstream water diversions have limited freshwater input during the last century, mollusc remains from the last several hundred years suggest widespread ecological change. The once abundant clam Mulinia modesta has undergone population declines of approximately 94% and populations of predators relying on this species as a food source have probably declined, switched to alternative prey species or both. We distinguish between the first two hypotheses using a null model of predation preference to test whether M. modesta was preyed upon selectively by the naticid snail, Neverita reclusiana , along the estuary's past salinity gradient. To evaluate the third hypothesis, we estimate available prey biomass today and in the past, assuming prey were a limiting resource. Data on the frequency of drill holes-identifiable traces of naticid predation on prey shells-showed several species, including M. modesta , were preferred prey. Neverita reclusiana was probably able to switch prey. Available prey biomass also declined, suggesting the N. reclusiana population probably also declined. These results indicate a substantial change to the structure of the benthic food web. Given the global scale of water management, such changes have probably also occurred in many of the world's estuaries. © 2018 The Author(s).

  4. Water Footprint of Industrial Tomato Cultivations in the Pinios River Basin: Soil Properties Interactions

    Directory of Open Access Journals (Sweden)

    Eleftherios Evangelou

    2016-11-01

    Full Text Available Industrial tomatoes are cultivated in about 4000 ha of the Pinios river basin (central Greece, providing significant income to the farmers. In this study, the water footprint (WF of industrial tomatoes between planting and harvest was estimated in 24 different farms for three consecutive years. The selected farms were representative of the main agro-climatic zones and soil textural classes within the river basin. Green, blue and grey WF calculations were based on datasets of the experimental plots for each farm, including irrigation water volume, meteorological, soil, and crop yield data. The results showed that the WF of tomatoes ranged from 37 to 131 m3 water/ton tomatoes with an average of 61 m3/ton. The WF variation depended mainly on crop yield, local agro-climatic and soil conditions. The green, blue, and grey WF components averaged 13, 27 and 21 m3/ton, respectively. The results reveal the importance of WF in understanding how tomato production relates to the sustainable use of freshwater and pollution at local level.

  5. Multi-scale nitrate transport in a sandstone aquifer system under intensive agriculture

    Science.gov (United States)

    Paradis, Daniel; Ballard, Jean-Marc; Lefebvre, René; Savard, Martine M.

    2018-03-01

    Nitrate transport in heterogeneous bedrock aquifers is influenced by mechanisms that operate at different spatial and temporal scales. To understand these mechanisms in a fractured sandstone aquifer with high porosity, a groundwater-flow and nitrate transport model—reproducing multiple hydraulic and chemical targets—was developed to explain the actual nitrate contamination observed in groundwater and surface water in a study area on Prince Edward Island, Canada. Simulations show that nitrate is leached to the aquifer year-round, with 61% coming from untransformed and transformed organic sources originating from fertilizers and manure. This nitrate reaches the more permeable shallow aquifer through fractures in weathered sandstone that represent only 1% of the total porosity (17%). Some of the nitrate reaches the underlying aquifer, which is less active in terms of groundwater flow, but most of it is drained to the main river. The river-water quality is controlled by the nitrate input from the shallow aquifer. Groundwater in the underlying aquifer, which has long residence times, is also largely influenced by the diffusion of nitrate in the porous sandstone matrix. Consequently, following a change of fertilizer application practices, water quality in domestic wells and the river would change rapidly due to the level of nitrate found in fractures, but a lag time of up to 20 years would be necessary to reach a steady level due to diffusion. This demonstrates the importance of understanding nitrate transport mechanisms when designing effective agricultural and water management plans to improve water quality.

  6. Karst connections between unconfined aquifers and the Upper Floridan aquifer in south Georgia: geophysical evidence and hydrogeological models

    Science.gov (United States)

    Thieme, D. M.; Denizman, C.

    2011-12-01

    Buried karst features in sedimentary rocks of the south Georgia Coastal Plain present a challenge for hydrogeological models of recharge and confined flow within the underlying Upper Floridan aquifer. The Withlacoochee River, the trunk stream for the area, frequently disappears into subsurface caverns as it makes its way south to join the Suwannee River in northern Florida. The Withlacoochee also receives inputs from small ponds and bays which in turn receive spring and seep groundwater inputs. We have mapped karst topography at the "top of rock" using ground-penetrating radar (GPR). Up to seven meters of relief is indicated for the paleotopography on Miocene to Pliocene rocks, contrasting with the more subdued relief of the modern landscape. Current stratigraphic and hydrogeological reconstructions do not incorporate this amount of relief or lateral variation in the confining beds. One "pipe" which is approximately four meters in diameter is being mapped in detail. We have field evidence at this location for rapid movement of surficial pond and river water with a meteoric signature through several separate strata of sedimentary rock into an aquifer in the Hawthorn formation. We use our geophysical and hydrological field evidence to constrain quantitative hydrogeological models for the flow rates into and out of both this upper aquifer and the underlying Upper Floridan aquifer, which is generally considered to be confined by the clays of the Hawthorn.

  7. A conceptual model of the hydrogeologic framework, geochemistry, and groundwater-flow system of the Edwards-Trinity and related aquifers in the Pecos County region, Texas

    Science.gov (United States)

    Bumgarner, Johnathan R.; Stanton, Gregory P.; Teeple, Andrew; Thomas, Jonathan V.; Houston, Natalie A.; Payne, Jason; Musgrove, MaryLynn

    2012-01-01

    measured in a faulted area of the Monument Draw trough. Hydraulic conductivity values generally exhibited the same trends as the transmissivity values. Groundwater-quality data and groundwater-level data were used in context with the hydrogeologic framework to assess the chemical characteristics of water from different sources, regional groundwater-flow paths, recharge sources, the mixing of water from different sources, and discharge in the study area. Groundwater-level altitudes generally decrease from southwest to northeast and regional groundwater flow is from areas of recharge south and west to the north and northeast. Four principal sources of recharge to the Edwards-Trinity aquifer were identified: (1) regional flow that originated as recharge northwest of the study area, (2) runoff from the Barilla, Davis, and Glass Mountains, (3) return flow from irrigation, and (4) upwelling from deeper aquifers. Results indicated Edwards-Trinity aquifer water in the study area was dominated by mineralized, regional groundwater flow that most likely recharged during the cooler, wetter climates of the Pleistocene with variable contributions of recent, local recharge. Groundwater generally flows into the down-dip extent of the Edwards-Trinity aquifer where it discharges into overlying or underlying aquifer units, discharges from springs, discharges to the Pecos River, follows a regional flow path east out of the study area, or is withdrawn by groundwater wells. Structural features such as mountains, troughs, and faults play a substantial role in the distribution of recharge, local and regional groundwater flow, spring discharge, and aquifer interaction.

  8. Natural isotopes and water stratification in the Judea Group aquifer (Judea Desert)

    International Nuclear Information System (INIS)

    Kornfeld, Loel; Vogel, John C.; Rosenthal, Asher

    1992-01-01

    Using environmental isotopes, the subaquifer of the Judea Group carbonate aquifer were studied from the recharge area in the Judea Hills, eastwords down the flanks of the escarpment to the Jordan River Valley. The oxygen isotope data confirms that the dominant source of recharge for the phreatic and confined subaquifers in the Judean Hills. Water-rock interactions develop the δ 13 C values rapidly in the recharge region. once established where is no significant subsequent modification due to interaction with the enveloping carbonate as the water travels down dip. The relative high tritium values encountered in the springs and several of the well waters would indicate modern waters. However, the low radiocarbon levels are often encountered in the same water sources implies that a mixture of young water with significanly older water has been encountered. There are indications, at least in the upper subaquifer, of agewise stratification of the waters. Water is transmitted very rapidly through the upper portions of the aquifer while the water in the lower portions may be moving slowly because of the low permeability. The timing of the recharge of the deeper portion of the subaquifer and much of the lower subaquifer occurred in the mid-to early Holocene. (authors)

  9. Modeling invasive alien plant species in river systems: Interaction with native ecosystem engineers and effects on hydro-morphodynamic processes

    Science.gov (United States)

    van Oorschot, M.; Kleinhans, M. G.; Geerling, G. W.; Egger, G.; Leuven, R. S. E. W.; Middelkoop, H.

    2017-08-01

    Invasive alien plant species negatively impact native plant communities by out-competing species or changing abiotic and biotic conditions in their introduced range. River systems are especially vulnerable to biological invasions, because waterways can function as invasion corridors. Understanding interactions of invasive and native species and their combined effects on river dynamics is essential for developing cost-effective management strategies. However, numerical models for simulating long-term effects of these processes are lacking. This paper investigates how an invasive alien plant species affects native riparian vegetation and hydro-morphodynamics. A morphodynamic model has been coupled to a dynamic vegetation model that predicts establishment, growth and mortality of riparian trees. We introduced an invasive alien species with life-history traits based on Japanese Knotweed (Fallopia japonica), and investigated effects of low- and high propagule pressure on invasion speed, native vegetation and hydro-morphodynamic processes. Results show that high propagule pressure leads to a decline in native species cover due to competition and the creation of unfavorable native colonization sites. With low propagule pressure the invader facilitates native seedling survival by creating favorable hydro-morphodynamic conditions at colonization sites. With high invader abundance, water levels are raised and sediment transport is reduced during the growing season. In winter, when the above-ground invader biomass is gone, results are reversed and the floodplain is more prone to erosion. Invasion effects thus depend on seasonal above- and below ground dynamic vegetation properties and persistence of the invader, on the characteristics of native species it replaces, and the combined interactions with hydro-morphodynamics.

  10. Interactions between Rotavirus and Suwannee River Organic Matter: Aggregation, Deposition, and Adhesion Force Measurement

    KAUST Repository

    Gutierrez, Leonardo; Nguyen, Thanh H.

    2012-01-01

    M, rotavirus suspension remained stable for over 4 h. Atomic force microscopy (AFM) measurement for interaction force decay length at different ionic strengths showed that nonelectrostatic repulsive forces were mainly responsible for eliminating aggregation

  11. Hydrogeochemical and Isotopic Characteristics of Tufa Precipitating Wates: A Case Study of the River Krka (Slovenia)

    Energy Technology Data Exchange (ETDEWEB)

    Zavadlav, S.; Lojen, S. [Jozef Stefan Institute, Department of Environmental Sciences, Ljubljana (Slovenia)

    2013-07-15

    The geochemical and stable isotope composition of tufa precipitating water in the River Krka in the Slovenian karst area were studied. Surface water chemistry in the River Krka is controlled by groundwater interactions with carbonate rocks, soil CO{sub 2} and meteoric water in the aquifer. Major element chemistry of water is controlled by dissolution of dolomite and calcite. The aquifer is the main source of cations, since concentrations of Mg{sup 2+}, Sr{sup 2+} and Ba{sup 2+} in water are highest at the spring. Ca{sup 2+} concentrations are slightly increasing due to the additional mixing of surface and groundwater downstream. Oxygen isotope composition of water indicates homogenization of meteoric water in the aquifer, while {delta}{sup 13}C values of dissolved inorganic carbon in water are affected by biological activity in the soil. {delta}{sup 18}O and {delta}{sup 13}C of bulk tufa show that deposition of tufa precipitates in the River Krka is kinetically controlled resulting in enrichment with heavier isotopes. Calculated equilibrium temperature of tufa precipitation based on the oxygen isotope composition of water and tufa fit with measured water temperature when average {delta}{sup 18}O values of water and tufa are considered. (author)

  12. Hydrochemistry and isotope geochemistry as management tools for groundwater resources in multilayer aquifers: A study case from the Po plain (Lomellina, South-Western Lombardy, Italy)

    Energy Technology Data Exchange (ETDEWEB)

    Pilla, G; Sacchi, E; Ciancetti, G; Braga, G [Dipartimento di Scienze della Terra, Universita di Pavia, Pavia (Italy); Zuppi, G M [Dipartimento di Scienze Ambientali, Universita Ca' Foscari di Venezia, Venice (Italy)

    2003-07-01

    Full text: The Po plain, located in Northern Italy, hosts a multi-layer alluvial aquifer of Quaternary age constituted by sands interbedded with clays. The plain supports most of the agricultural and industrial activities of Northern Italy, which are associated with groundwater pollution in the shallower portions of the aquifer. The increasing demand of water for industrial and domestic use has led to the exploitation of deeper layers of the aquifer, without a rational management of the resource. Only in the last decade, the government agencies have started a global evaluation of the quality standards of pumped groundwater, urged by the increasing need for clean water for domestic use. The task is particularly difficult because of missing or approximate well logs and the presence of multi-filter wells tapping in different aquifers. In this case the chemical and isotopic characterisation of groundwaters is the only reliable tool to reconstruct the geometry, the interconnections and the characteristics of the aquifers. This study, promoted by the local agency for groundwater management and protection (Amministrazione Provinciale di Pavia, settore tutela e valorizzazione ambientale - U.O.C. Acqua) focused on a limited portion of the Po plain, the Lomellina region, of approximately 900 km{sup 2}. The region is bound to the South by the Po river, to the East and West by the Sesia and the Ticino rivers respectively, and to the North by the administrative boundary. The study aimed at the hydrogeological, hydrochemical and isotopic characterisation of the aquifers, allowing to serve as basis for the correct management of the groundwater resource. A preliminary reconstruction of the hydrogeological asset of the Lomellina plain was performed through the analysis of the stratigraphic data from 102 municipal wells. On this basis, a shallow phreatic aquifer, reaching depths of about 50-60 m from the surface, and two groups of aquifers containing confined groundwater, were

  13. Groundwater salinity in coastal aquifer of Karachi, Pakistan

    International Nuclear Information System (INIS)

    Mashiatullah, A.; Qureshi, R.M.; Ahmad, E.; Tasneem, M.A.; Sajjad, M.I.; Khan, H.A.

    2002-01-01

    Potable groundwater salinity has become a problem of great concern in the Karachi Metropolis, which is not only the most populous and biggest industrial base but also the largest coastal dwelling of Pakistan. Stable isotope techniques [O/sup 18/ content of Oxygen in the water molecular and C/sup 13/ content of the Total Dissolved Inorganic Carbon (TDIC)] have been used, in conjunction with physiochemical tools (temperature, dissolved oxygen, pH, redox electrical conductivity, salinity), to examine the quality of potable water and the source of salinity. Surface water samples (12 No.) were collected from polluted streams, namely: Layeri River, Malir River; Hub River/Hub Lake and the Indus River. Shallow groundwater samples (7 No. ) were collected from operating dug wells. Relatively deep groundwater samples (12 No.) were collected from operating dug wells, relatively deep groundwater samples (12 No.) were collected from pumping wells/tube-wells. Physicochemical analysis of water samples was completed in the field. In the laboratory, water samples were analyzed for O/sup 18/ content of oxygen in the water molecule and C/sup 13/ content of the TDIC, using specific gas extraction systems and a modified GD-150 gas source mass spectrometer. It is concluded from this preliminary investigation that the potable aquifer system in coastal Karachi hosts a mixture of precipitation (rainwater only) from hinterlands, trapped seawater in relatively deep aquifer system, as well as intruded seawater under natural infiltration conditions and/or induced recharge conditions (in shallow aquifers). (author)

  14. Is high-resolution inverse characterization of heterogeneous river bed hydraulic conductivities needed and possible?

    Directory of Open Access Journals (Sweden)

    W. Kurtz

    2013-10-01

    Full Text Available River–aquifer exchange fluxes influence local and regional water balances and affect groundwater and river water quality and quantity. Unfortunately, river–aquifer exchange fluxes tend to be strongly spatially variable, and it is an open research question to which degree river bed heterogeneity has to be represented in a model in order to achieve reliable estimates of river–aquifer exchange fluxes. This research question is addressed in this paper with the help of synthetic simulation experiments, which mimic the Limmat aquifer in Zurich (Switzerland, where river–aquifer exchange fluxes and groundwater management activities play an important role. The solution of the unsaturated–saturated subsurface hydrological flow problem including river–aquifer interaction is calculated for ten different synthetic realities where the strongly heterogeneous river bed hydraulic conductivities (L are perfectly known. Hydraulic head data (100 in the default scenario are sampled from the synthetic realities. In subsequent data assimilation experiments, where L is unknown now, the hydraulic head data are used as conditioning information, with the help of the ensemble Kalman filter (EnKF. For each of the ten synthetic realities, four different ensembles of L are tested in the experiments with EnKF; one ensemble estimates high-resolution L fields with different L values for each element, and the other three ensembles estimate effective L values for 5, 3 or 2 zones. The calibration of higher-resolution L fields (i.e. fully heterogeneous or 5 zones gives better results than the calibration of L for only 3 or 2 zones in terms of reproduction of states, stream–aquifer exchange fluxes and parameters. Effective L for a limited number of zones cannot always reproduce the true states and fluxes well and results in biased estimates of net exchange fluxes between aquifer and stream. Also in case only 10 head data are used for conditioning, the high

  15. Processes Affecting Groundwater Quality in the La Digue Aquifer, Seychelles

    Energy Technology Data Exchange (ETDEWEB)

    Alcindor, A. [Public Utilities Corporation, Victoria (Seychelles); Sacchi, E. [Dipartimento di Scienze della Terra e dell' ambiente, Universita di Pavia (Italy); Taigbenu, A. E. [University of the Witwatersrand, Johannesburg (South Africa)

    2013-07-15

    This paper presents the results obtained by the public utilities corporation (PUC), within the framework of an IAEA TC project, which aims to evaluate the potential of the la digue aquifer. Several monitoring activities and hydrochemical and isotopic surveys have been conducted. Results indicate the presence of brackish water at shallow depths, and low redox potentials, attesting to the presence of H{sub 2}S and heavy metals. Groundwater quality is affected by the concomitant presence of different adverse factors, namely aquifer characteristics, hydrogeology, and anthropogenic pressure. In addition, seawater penetrates the river course during high tides and infiltrates through the recharge area of the aquifer that is close to the actual pumping station. The positioning of non return high tide gates, an easy and low cost intervention, could enhance groundwater quality. The understanding of the main processes affecting groundwater quality helped in the identification of areas favourable for new wells, located at higher elevations. (author)

  16. Interactions of Multiple Atmospheric Circulation Drive the Drought in Tarim River Basin

    Science.gov (United States)

    Wu, Yong-Ping; Feng, Guo-Lin; Li, Bai-Lian

    2016-05-01

    Global warming is likely to cause overall drying of land surfaces and aridity increasing leading to expansion of dry climate zones. There is an increased risk of extremely arid environment and large deserts developed progressively in the central Asia. However, the key factors causing the drying in mid-Asia remain inconclusive. Here, we analyzed the relationship among precipitation, water vapor transportation in Tarim River Basin (TRB) and Multiple Atmospheric Circulation (MAC) to explore the mechanism of MAC driving the drying in TRB, through comparing MAC between abundant and scarce precipitation years. We found that Westerly Circulation (WC) and Asian Summer Monsoon (ASM) are likely to promote the precipitation respectively. Whereas, they not only have their own influence but also restrict each other and facilitate the forming of peculiar water vapor transport channel for TRB, which is probably to restrain the precipitation and its distribution pattern and accelerate the drying in this region. Our results enrich the findings on mechanisms of wet places becoming wetter while dry areas getting drier under the global warming.

  17. Impact of climate change on freshwater resources in a heterogeneous coastal aquifer of Bremerhaven, Germany: A three-dimensional modeling study.

    Science.gov (United States)

    Yang, Jie; Graf, Thomas; Ptak, Thomas

    2015-01-01

    Climate change is expected to induce sea level rise in the German Bight, which is part of the North Sea, Germany. Climate change may also modify river discharge of the river Weser flowing into the German Bight, which will alter both pressure and salinity distributions in the river Weser estuary. To study the long-term interaction between sea level rise, discharge variations, a storm surge and coastal aquifer flow dynamics, a 3D seawater intrusion model was designed using the fully coupled surface-subsurface numerical model HydroGeoSphere. The model simulates the coastal aquifer as an integral system considering complexities such as variable-density flow, variably saturated flow, irregular boundary conditions, irregular land surface and anthropogenic structures (e.g., dyke, drainage canals, water gates). The simulated steady-state groundwater flow of the year 2009 is calibrated using PEST. In addition, four climate change scenarios are simulated based on the calibrated model: (i) sea level rise of 1m, (ii) the salinity of the seaside boundary increases by 4 PSU (Practical Salinity Units), (iii) the salinity of the seaside boundary decreases by 12 PSU, and (iv) a storm surge with partial dyke failure. Under scenarios (i) and (iv), the salinized area expands several kilometers further inland during several years. Natural remediation can take up to 20 years. However, sudden short-term salinity changes in the river Weser estuary do not influence the salinized area in the coastal aquifer. The obtained results are useful for coastal engineering practices and drinking water resource management. Copyright © 2015 Elsevier B.V. All rights reserved.

  18. Cleveland-Akron Metropolitan and Three Rivers Watershed Area. Wastewater Management Survey Scope Study. Appendix V. Land Treatment. Phase I Report.

    Science.gov (United States)

    1973-08-01

    Service provided the foundation for this I inventory of potential land treatment areas. The analysis and inventory of these data resulted in the...degree required for bedrock derived ground water. Chemical analysis was available from only one well water sample in the buried river valley aquifer...as lignin, waxes, tannins , cutins and fats are more resistant to decomposition. I I I ’I I I 168 I I I NUTRIENT UPTAKE Interactions between organic

  19. Changes in the Regional Groundwater Aquifer and Potential Impacts on Surface Waters in Central Zealand, Denmark

    DEFF Research Database (Denmark)

    Thorn, Paul

    The regional, confined aquifer on the island of Zealand, in eastern Denmark, is the primary aquifer used for large-scale abstraction for the supplies of all larger cities, including Roskilde and the greater Copenhagen metropolitan area. Large-scale groundwater abstraction from this aquifer...... in the area near Lejre Denmark (approximately 15km to the SW of Roskilde) began in 1937, exporting approximately 18 million m3 of water per year to supply the city of Copenhagen. After abstraction began, streams in the area were observed to go dry after extended periods without precipitation, where......, wetlands and lakes in the area. The results show that there was a significant impact on the regional groundwater aquifer in the Langvad river catchment, with groundwater as much as 17m lower in 1987 from 1936 (pre-abstraction). However, in the Elverdam river catchment, the levels remained virtually...

  20. Review of potential interactions between stocked rainbow trout and listed Snake River sockeye salmon in Pettit Lake Idaho

    Energy Technology Data Exchange (ETDEWEB)

    Teuscher, D.

    1996-05-01

    The objective of this study was to determine if hatchery rainbow trout compete with or prey on juvenile Snake River sockeye salmon Oncorhynchus nerka in Pettit Lake, Idaho. In 1995, a total of 8,570 age-0 sockeye and 4,000 hatchery rainbow trout were released in Pettit Lake. After releasing the fish, gillnets were set in the pelagic and littoral zones to collected diet and spatial distribution data. Interactions were assessed monthly from June 1995 through March 1996. Competition for food was discounted based on extremely low diet overlap results observed throughout the sample period. Conversely, predation interactions were more significant. A total of 119 rainbow trout stomachs were analyzed, two contained O. nerka. The predation was limited to one sample period, but when extrapolated to the whole rainbow trout populations results in significant losses. Total consumption of O. nerka by rainbow trout ranged from an estimated 10 to 23% of initial stocking numbers. Predation results contradict earlier findings that stocked rainbow trout do not prey on wild kokanee or sockeye in the Sawtooth Lakes. The contradiction may be explained by a combination of poorly adapted hatchery sockeye and a littoral release site that forced spatial overlap that was not occurring in the wild populations. Releasing sockeye in the pelagic zone may have reduced or eliminated predation losses to rainbow trout.

  1. Review of potential interactions between stocked rainbow trout and listed Snake River sockeye salmon in Pettit Lake Idaho

    International Nuclear Information System (INIS)

    Teuscher, D.

    1996-01-01

    The objective of this study was to determine if hatchery rainbow trout compete with or prey on juvenile Snake River sockeye salmon Oncorhynchus nerka in Pettit Lake, Idaho. In 1995, a total of 8,570 age-0 sockeye and 4,000 hatchery rainbow trout were released in Pettit Lake. After releasing the fish, gillnets were set in the pelagic and littoral zones to collected diet and spatial distribution data. Interactions were assessed monthly from June 1995 through March 1996. Competition for food was discounted based on extremely low diet overlap results observed throughout the sample period. Conversely, predation interactions were more significant. A total of 119 rainbow trout stomachs were analyzed, two contained O. nerka. The predation was limited to one sample period, but when extrapolated to the whole rainbow trout populations results in significant losses. Total consumption of O. nerka by rainbow trout ranged from an estimated 10 to 23% of initial stocking numbers. Predation results contradict earlier findings that stocked rainbow trout do not prey on wild kokanee or sockeye in the Sawtooth Lakes. The contradiction may be explained by a combination of poorly adapted hatchery sockeye and a littoral release site that forced spatial overlap that was not occurring in the wild populations. Releasing sockeye in the pelagic zone may have reduced or eliminated predation losses to rainbow trout

  2. Conceptual and numerical modeling approach of the Guarani Aquifer System

    Directory of Open Access Journals (Sweden)

    L. Rodríguez

    2013-01-01

    Full Text Available In large aquifers, relevant for their considerable size, regional groundwater modeling remains challenging given geologic complexity and data scarcity in space and time. Yet, it may be conjectured that regional scale groundwater flow models can help in understanding the flow system functioning and the relative magnitude of water budget components, which are important for aquifer management. The Guaraní Aquifer System is the largest transboundary aquifer in South America. It contains an enormous volume of water; however, it is not well known, being difficult to assess the impact of exploitation currently used to supply over 25 million inhabitants. This is a sensitive issue because the aquifer is shared by four countries. Moreover, an integrated groundwater model, and therefore a global water balance, were not available. In this work, a transient regional scale model for the entire aquifer based upon five simplified, equally plausible conceptual models represented by different hydraulic conductivity parametrizations is used to analyze the flow system and water balance components. Combining an increasing number of hydraulic conductivity zones and an appropriate set of boundary conditions, the hypothesis of a continuous sedimentary unit yielded errors within the calibration target in a regional sense. The magnitude of the water budget terms resulted very similar for all parametrizations. Recharge and stream/aquifer fluxes were the dominant components representing, on average, 84.2% of total inflows and 61.4% of total outflows, respectively. However, leakage was small compared to stream discharges of main rivers. For instance, the simulated average leakage for the Uruguay River was 8 m3 s−1 while the observed absolute minimum discharge was 382 m3 s−1. Streams located in heavily pumped regions switched from a gaining condition in early years to a losing condition over time. Water is discharged through

  3. Conceptual and numerical modeling approach of the Guarani Aquifer System

    Science.gov (United States)

    Rodríguez, L.; Vives, L.; Gomez, A.

    2013-01-01

    In large aquifers, relevant for their considerable size, regional groundwater modeling remains challenging given geologic complexity and data scarcity in space and time. Yet, it may be conjectured that regional scale groundwater flow models can help in understanding the flow system functioning and the relative magnitude of water budget components, which are important for aquifer management. The Guaraní Aquifer System is the largest transboundary aquifer in South America. It contains an enormous volume of water; however, it is not well known, being difficult to assess the impact of exploitation currently used to supply over 25 million inhabitants. This is a sensitive issue because the aquifer is shared by four countries. Moreover, an integrated groundwater model, and therefore a global water balance, were not available. In this work, a transient regional scale model for the entire aquifer based upon five simplified, equally plausible conceptual models represented by different hydraulic conductivity parametrizations is used to analyze the flow system and water balance components. Combining an increasing number of hydraulic conductivity zones and an appropriate set of boundary conditions, the hypothesis of a continuous sedimentary unit yielded errors within the calibration target in a regional sense. The magnitude of the water budget terms resulted very similar for all parametrizations. Recharge and stream/aquifer fluxes were the dominant components representing, on average, 84.2% of total inflows and 61.4% of total outflows, respectively. However, leakage was small compared to stream discharges of main rivers. For instance, the simulated average leakage for the Uruguay River was 8 m3 s-1 while the observed absolute minimum discharge was 382 m3 s-1. Streams located in heavily pumped regions switched from a gaining condition in early years to a losing condition over time. Water is discharged through the aquifer boundaries, except at the eastern boundary. On average

  4. Massive production of heavy metals in the Ganga (Hooghly) River estuary, India: Global importance of solute-particle interaction and enhanced metal fluxes to the oceans

    Science.gov (United States)

    Samanta, Saumik; Dalai, Tarun K.

    2018-05-01

    The Ganga River System is a major contributor to the global sediment and water discharge to the oceans. The estuary of Ganga (Hooghly) River in India is under increasing influence of anthropogenic contributions via discharge of the industrial and urban effluents. Here we document, based on the investigation of water and suspended sediment samples collected during six periods over two years, that there is extensive production of heavy metals (Co, Ni and Cu) in the estuary such that the annual dissolved fluxes of metals from the Hooghly River are enhanced by up to 230-1770%. Furthermore, the estuarine dissolved metal fluxes, when normalized with water fluxes, are the highest among estuaries of the major rivers in the world. Our simultaneous data on the dissolved, suspended particulate and exchangeable phases allow us to identify the ion-exchange process (coupled adsorption and desorption) as the dominant contributor to the generation of heavy metals in the middle and lower estuary where the estimated anthropogenic contribution is negligible. The estimated contributions from the groundwater are also insufficient to explain the measured metal concentrations in the estuary. A strong positive correlation that is observed between the dissolved heavy metal fluxes and the suspended particulate matter (SPM) fluxes, after normalizing them with the water fluxes, for estuaries of the major global rivers imply that the solute-particle interaction is a globally significant process in the estuarine production of metals. Based on this correlation that is observed for major estuaries around the world, we demonstrate that the South Asian Rivers which supply only ∼9% of the global river water discharge but carry elevated SPM load, contribute a far more significant proportion (∼40 ± 2% Ni and 15 ± 1% Cu) to the global supply of the dissolved metals from the rivers.

  5. Hydrochemical processes in a shallow coal seam gas aquifer and its overlying stream–alluvial system: implications for recharge and inter-aquifer connectivity

    International Nuclear Information System (INIS)

    Duvert, Clément; Raiber, Matthias; Owen, Daniel D.R.; Cendón, Dioni I.; Batiot-Guilhe, Christelle; Cox, Malcolm E.

    2015-01-01

    Highlights: • Major ions and isotopes used to study inter-aquifer mixing in a shallow CSG setting. • Considerable heterogeneity in the water composition of the coal-bearing aquifer. • Rapid recharge of the coal-bearing aquifer through highly fractured igneous rocks. • Potential mixing between the coal-bearing aquifer and downstream alluvial aquifer. • Need to consider the seasonal influences on inter-aquifer mixing in CSG settings. - Abstract: In areas of potential coal seam gas (CSG) development, understanding interactions between coal-bearing strata and adjacent aquifers and streams is of highest importance, particularly where CSG formations occur at shallow depth. This study tests a combination of hydrochemical and isotopic tracers to investigate the transient nature of hydrochemical processes, inter-aquifer mixing and recharge in a catchment where the coal-bearing aquifer is in direct contact with the alluvial aquifer and surface drainage network. A strong connection was observed between the main stream and underlying alluvium, marked by a similar evolution from fresh Ca–Mg–HCO 3 waters in the headwaters towards brackish Ca–Na–Cl composition near the outlet of the catchment, driven by evaporation and transpiration. In the coal-bearing aquifer, by contrast, considerable site-to-site variations were observed, although waters generally had a Na–HCO 3 –Cl facies and high residual alkalinity values. Increased salinity was controlled by several coexisting processes, including transpiration by plants, mineral weathering and possibly degradation of coal organic matter. Longer residence times and relatively enriched carbon isotopic signatures of the downstream alluvial waters were suggestive of potential interactions with the shallow coal-bearing aquifer. The examination of temporal variations in deuterium excess enabled detection of rapid recharge of the coal-bearing aquifer through highly fractured igneous rocks, particularly at the catchment

  6. Yakima River Species Interactions Studies; Yakima/Klickitat Fisheries Project Monitoring and Evaluation, 2004-2005 Annual Report.

    Energy Technology Data Exchange (ETDEWEB)

    Pearsons, Todd N.; Temple, Gabriel M.; Fritts, Anthony L. (Washington Department of Fish and Wildlife, Olympia, WA)

    2005-05-01

    This report is intended to satisfy two concurrent needs: (1) provide a contract deliverable from the Washington Department of Fish and Wildlife (WDFW) to the Bonneville Power Administration (BPA), with emphasis on identification of salient results of value to ongoing Yakima/Klickitat Fisheries Project (YKFP) planning, and (2) summarize results of research that have broader scientific relevance. This is the thirteenth of a series of progress reports that address species interactions research and supplementation monitoring of fishes in response to supplementation of salmon and steelhead in the upper Yakima River basin (Hindman et al. 1991; McMichael et al. 1992; Pearsons et al. 1993; Pearsons et al. 1994; Pearsons et al. 1996; Pearsons et al. 1998, Pearsons et al. 1999, Pearsons et al. 2001a, Pearsons et al. 2001b, Pearsons et al. 2002, Pearsons et al. 2003, Pearsons et al. 2004)